part ok

AGENTS.md

@@ -2,12 +2,12 @@
 
 ## Project Status
 
-Project initialized — `webui/` (React Native) and `backend/` (Go) have scaffolding in place.
+Project initialized — `mobile/` (React Native / Expo) and `backend/` (Go) have scaffolding in place. The SQLite layer (schema v4, migrations, repositories) is implemented and covered by tests.
 
 ## Architecture
 
 - **Backend**: Go, Gin HTTP framework, PostgreSQL, Tesseract OCR (system call)
-- **Frontend**: React Native (Expo SDK 57), React Navigation, TanStack Query, react-native-image-picker
+- **Frontend**: React Native (Expo SDK 57), expo-router, expo-sqlite, expo-file-system (SAF)
 
 ## Key Commands
 
@@ -19,10 +19,13 @@ cd backend && go run cmd/server/main.go
 docker compose up postgres -d
 
 # Frontend
-cd webui && npx expo start
+cd mobile && npx expo start
 
 # Typecheck frontend
-cd webui && npx tsc --noEmit
+cd mobile && npx tsc --noEmit
+
+# SQLite layer tests (migrations + repositories)
+cd mobile && npm run test:db
 ```
 
 ## Backend Structure
@@ -38,17 +41,31 @@ cd webui && npx tsc --noEmit
 
 ## Frontend Structure
 
-- Entry point: `webui/App.tsx` (React Navigation + TanStack Query providers)
-- Screens: `app/index.tsx` (home), `app/upload.tsx`, `app/scan.tsx`, `app/search.tsx`
-- Components: `components/FileCard.tsx`, `TagChip.tsx`, `UploadProgress.tsx`
-- Hooks: `hooks/useFiles.ts`, `hooks/useSearch.ts`, `hooks/useUpload.ts`
-- API client: `api/client.ts`, types: `types/index.ts`, constants: `constants/api.ts`
-- No business logic on the client — all heavy processing server-side
-- API base URL configured via `EXPO_PUBLIC_API_BASE_URL` env var
+- Entry point: `mobile/App.tsx` (expo-router layout + Auth context)
+- Data layer — `mobile/services/`:
+  - `safDirectory.ts` + `safDirectory.types.ts`: physical access via `expo-file-system` (pick/list/create, Documents/SAF uris)
+  - `db/` — SQLite persistence, see `mobile/AGENTS.md` for the full contract (schema, migrations, repositories, tests)
+  - `localStorage.ts` — thin re-export of `services/db` (legacy alias)
+- `features/syncDevice.ts` — device sync orchestration (two-pass SAF walk, single transaction per root, `exists = 0` reconciliation)
+- `context/AuthContext.tsx` — session context
+- No business logic on the client — heavy processing stays server-side
+- API base URL configured via `EXPO_PUBLIC_API_BASE_URL` env var (client + hooks not yet built)
+
+## Data Conventions
+
+- Canonical identity for folders/files/shares/share_links is `resource_id`: opaque `lower(hex(randomblob(16)))`, generated locally, never reused. The physical `uri` is nullable (NULL = cloud-only) and is the reconciliation key for the SAF walk.
+- `owner_id` is NOT NULL on every folder/file row, seeded from the device's `device_user_id`.
+- Folder/file `sync_status` is a **placement** state: `local` | `cloud` | `local-cloud` (transitions via `transitionSyncStatus`). It is not a push progress marker.
+- Shares/share_links carry no `sync_status`; their `pushStatus` (pending/synced/failed) is derived from the `pending_operations` outbox.
+- Decisions are made **offline** from a cached `resource_permissions` snapshot pushed by the server; the server remains the source of truth. `canAccess` enforces ranking (viewer < commenter < editor < owner), `inherit`, `expires_at`, and a 24h stale-cache read-only downgrade.
+- `password_hash` and download counters are **server-side only**; the client only stores the `has_password` boolean and a counter mirror.
 
 ## Non-Goals (V1)
 
-Collaborative/multi-user, plugin system, complex offline sync, public sharing.
+- Plugin system
+- On-device OCR
+- Full multi-tenant federation / public discovery
+- Multi-writer sync conflicts (single-owner device identity; device-local `device_user_id`)
 
 ## References
 

mobile/AGENTS.md

@@ -7,15 +7,17 @@ Read the exact versioned docs at https://docs.expo.dev/versions/v57.0.0/ before
 Persistence is SQLite-backed via `services/db/` (`expo-sqlite`, database `dot.db`, `user_version` = 4).
 
 - `services/db/client.ts` — connection lifecycle: `getDatabase()`, `closeDatabase()`, `withTransaction()`.
-- `services/db/migrations.ts` — versioned, chained migrations via `PRAGMA user_version` (list of `{ version, up }`), single-flight `WeakMap` lock, `migrateDatabase(db, targetVersion?)`. v4 is a **transactional rebuild** (folders/files drop `uri` keys, gain `resource_id`). Migration tests: `npm run test:migrations` (better-sqlite3 harness in `tests/migrations.test.ts`, run with `tsx`).
+- `services/db/migrations.ts` — versioned, chained migrations via `PRAGMA user_version` (list of `{ version, up }`), single-flight `WeakMap` lock, `migrateDatabase(db, targetVersion?)`. v4 is a **transactional rebuild** (folders/files drop `uri` keys, gain `resource_id` + partial unique index on non-null `uri`). Migration tests: `npm run test:migrations` (better-sqlite3 harness in `tests/migrations.test.ts`); repository tests: `npm run test:db` (both suites, better-sqlite3 via the `DbSession` seam).
+- `services/db/session.ts` — `DbSession` (injectable `runAsync`/`getFirstAsync`/`getAllAsync`) ; repos get it through `getSession()`, tests override it with `__setDbForTests()`. `client.ts` loads `expo-sqlite` lazily so the test suites run under plain Node.
 - `services/db/schema.ts` — `DATABASE_NAME`, `DATABASE_VERSION`, column-list constants, `DEVICE_USER_ID_KEY`, `PERMISSION_TTL_MS` (24h offline stale-cache).
 - `services/db/id.ts` — `newResourceId()` opaque 32-hex `lower(hex(randomblob(16)))`, generated per row.
 - `services/db/transitions.ts` — `transitionSyncStatus(from, event)`: per-row sync status transitions.
-- `services/db/repositories/` — one module per table: `folders`, `files`, `user_preferences` (+ `getDeviceUserId`), `resource_permissions` (`permissions.ts` with `canAccess`/`canWrite`/`isOwner`, hierarchical via `WITH RECURSIVE`), `shares`, `share_links`, `recipients`, `pending_operations` (`pendingOps.ts`, outbox).
+- `services/db/repositories/` — one module per table: `folders`, `files`, `user_preferences` (+ `getDeviceUserId`), `resource_permissions` (`permissions.ts` with `canAccess`/`canWrite`/`isOwner`, hierarchical via `WITH RECURSIVE`, `inherit`/`expires_at` honored, 24h stale-cache read-only downgrade), `shares`, `share_links`, `recipients`, `pending_operations` (`pendingOps.ts`, outbox: FIFO on `(created_at, id)`, failure schedules a `pending` retry with backoff, dead-letter `failed` after `MAX_PENDING_ATTEMPTS`).
 - `services/localStorage.ts` is a thin re-export (`services/db`) kept for legacy imports.
 - Tables: `folders`, `files`, `user_preferences`, `resource_permissions`, `shares`, `share_links`, `recipients`, `pending_operations`.
 - Canonical identity: `resource_id` (opaque, unique) on folders/files/shares/share_links; `uri` (physical SAF path) is **nullable**, NULL = cloud-only; `owner_id` NOT NULL seeded from `device_user_id`.
 - Folder and file per-row sync status: `local` | `cloud` | `local-cloud` (placement state, transitions via `transitionSyncStatus`).
 - `shares`/`share_links` have NO `sync_status`: their `pushStatus` (`pending`/`synced`/`failed`) is **derived** from `pending_operations` (`ref_type` = `share`|`share_link`, `ref_id`).
 - Query usage: `getFiles(folderResourceId?)`, `getFolders()`, `getFolderFolders(parentResourceId)`, `getFolder`/`getFile(resourceId)`, `saveFolder`/`saveDirectory`, `saveFile(file, folderResourceId)`, `removeFolder`/`removeFile(resourceId)`, `saveUserPreferences`/`getUserPreferences`/`getDeviceUserId`, `saveResourcePermission`/`getResourcePermission`, `canAccess(resourceId, type, level)`, `saveShare`/`getShares`/`removeShare`, `createShareLink`/`getShareLinks`/`incrementLinkDownloads`/`revokeShareLink`, `saveRecipient`/`getRecipients`, `enqueuePendingOperation`/`getNextQueuedOperation`/`markPendingOperation`.
+- SAF walk (`features/syncDevice.ts`, `syncDevice()`/`syncRoot()`): **two passes** (all folders sorted by uri depth, then all files) inside a **single transaction** (`withTransaction`), receives sync: an interruption rolls back entirely. Reconciles by physical `uri`; rows under the root with a `uri` no longer seen are **marked `exists = 0`** (never deleted). Root folders are the rows with `parent_resource_id IS NULL` + non-null `uri`.
 - Heavy processing stays server-side; SQLite only persists local metadata/state.

mobile/app/index.tsx

@@ -3,6 +3,7 @@ import { useEffect, useState } from 'react';
 import { Pressable, StyleSheet, Text, View } from 'react-native';
 import { pickDirectory } from '../services/safDirectory';
 import { saveDirectory, getFolders } from '../services/localStorage';
+import { syncRoot } from '../features/syncDevice';
 
 export default function Index() {
 
@@ -18,9 +19,14 @@ export default function Index() {
   const handlePickDirectory = async () => {
     const folder = await pickDirectory();
     if ( !folder ) return;
-    await saveDirectory(folder);
+    const saved = await saveDirectory(folder);
     setFolders((prev) => [...prev, folder.name]);
-    console.log(folders)
+    try {
+      const result = await syncRoot(saved.resource_id);
+      console.info('walk', JSON.stringify(result));
+    } catch (error) {
+      console.warn('walk failed', error);
+    }
   };
 
   return (

mobile/features/syncDevice.ts

@@ -1,47 +1,129 @@
-import { getUserPreferences } from "../services/localStorage";
-import type { UserPreferences } from "../services/localStorage"
+import { listDirectory, listFolders } from '../services/safDirectory';
+import type { FileEntry } from '../services/safDirectory.types';
+import {
+  getFiles,
+  getFolder,
+  getFolders,
+  saveFile,
+  saveFolder,
+  getUserPreferences,
+  withTransaction,
+  type StoredFile,
+  type StoredFolder,
+} from '../services/db';
 
-let syncStartedAt: null | number = null;
-
-export async function useSyncDevice() {
-
-    initialize()
-
-    async function initialize() {
-        
-        if ( syncStartedAt ) return;
-
-        syncStartedAt = Date.UTC(Date.now());
-
-        console.info("Sync started")
-
-        while (true) {
-
-            await sync()
-
-            await new Promise((resolve)=>{
-                setTimeout(() => {
-                    resolve(true)
-                }, 1000);
-            })
-        }
- 
-    }
-
-    async function sync() {
-
-        const userPreferences = await getUserPreferences()
-
-        console.log(userPreferences)
-
-    }
- 
-    async function setSyncMode( mode: UserPreferences ) {
-
-    }
-
-    return {
-
-    }
+export type SyncResult = {
+  rootUri: string;
+  folders: number;
+  files: number;
+  missing: number;
+};
 
+function uriDepth(uri: string): number {
+  return uri.split('/').length;
+}
+
+function dirname(uri: string): string {
+  return uri.slice(0, uri.lastIndexOf('/'));
+}
+
+function storedToEntry(stored: StoredFile): FileEntry {
+  return {
+    uri: stored.uri ?? '',
+    name: stored.name,
+    isDirectory: false,
+    extension: stored.extension,
+    exists: false,
+    size: stored.size,
+    type: stored.type,
+    lastModified: stored.lastModified,
+  };
+}
+
+function isChildOf(uri: string, rootUri: string): boolean {
+  return uri.startsWith(rootUri);
+}
+
+export async function syncRoot(rootResourceId: string): Promise<SyncResult> {
+  const root = await getFolder(rootResourceId);
+  if (!root) throw new Error('unknown root folder');
+  if (!root.uri) throw new Error(`root '${root.name}' has no physical uri`);
+
+  return withTransaction(async () => {
+    const seen = new Set<string>();
+
+    const folders = listFolders(root.uri as string, { recursive: true, includeRoot: true }).sort(
+      (a, b) => uriDepth(a.uri) - uriDepth(b.uri),
+    );
+
+    const resourceIdByUri = new Map<string, string>();
+    const savedFolders: StoredFolder[] = [];
+    for (const folder of folders) {
+      seen.add(folder.uri);
+      const parentUri = dirname(folder.uri);
+      const parentResourceId =
+        folder.uri === root.uri ? null : (resourceIdByUri.get(parentUri) ?? root.resource_id);
+      const saved = await saveFolder(
+        { uri: folder.uri, name: folder.name, exists: folder.exists },
+        { parentResourceId },
+      );
+      resourceIdByUri.set(folder.uri, saved.resource_id);
+      savedFolders.push(saved);
+    }
+
+    let files = 0;
+    for (const folder of savedFolders) {
+      if (!folder.uri) continue;
+      for (const entry of listDirectory(folder.uri)) {
+        if (entry.isDirectory) continue;
+        seen.add(entry.uri);
+        await saveFile(entry, folder.resource_id);
+        files++;
+      }
+    }
+
+    let missing = 0;
+    for (const folder of await getFolders()) {
+      if (folder.uri && isChildOf(folder.uri, root.uri as string) && folder.exists && !seen.has(folder.uri)) {
+        await saveFolder(
+          { uri: folder.uri, name: folder.name, exists: false, resource_id: folder.resource_id },
+          { syncStatus: folder.syncStatus },
+        );
+        missing++;
+      }
+    }
+    for (const file of await getFiles()) {
+      if (file.uri && isChildOf(file.uri, root.uri as string) && file.exists && !seen.has(file.uri)) {
+        await saveFile(storedToEntry(file), file.folder_resource_id, {
+          resource_id: file.resource_id,
+          syncStatus: file.syncStatus,
+        });
+        missing++;
+      }
+    }
+
+    return { rootUri: root.uri as string, folders: folders.length, files, missing };
+  });
+}
+
+export async function syncDevice(): Promise<SyncResult[]> {
+  const roots = (await getFolders()).filter(
+    (folder) => folder.parent_resource_id === null && folder.uri !== null,
+  );
+  const results: SyncResult[] = [];
+  for (const root of roots) {
+    results.push(await syncRoot(root.resource_id));
+  }
+  return results;
+}
+
+export async function useSyncDevice(intervalMs = 30_000): Promise<void> {
+  const preferences = await getUserPreferences();
+  if (preferences.syncMode === 'none') return;
+
+  while (true) {
+    const results = await syncDevice();
+    console.info('syncDevice', JSON.stringify(results));
+    await new Promise((resolve) => setTimeout(resolve, intervalMs));
+  }
 }

mobile/package.json

@@ -29,6 +29,7 @@
     "android": "expo run:android",
     "ios": "expo run:ios",
     "web": "expo start --web",
+    "test:db": "tsx --test tests/migrations.test.ts tests/repositories.test.ts",
     "test:migrations": "tsx --test tests/migrations.test.ts"
   },
   "private": true

mobile/services/db/client.ts

@@ -1,13 +1,17 @@
-import * as SQLite from 'expo-sqlite';
 import type { SQLiteDatabase } from 'expo-sqlite';
 import { migrateDatabase } from './migrations';
 import { DATABASE_NAME } from './schema';
 
 let database: SQLiteDatabase | null = null;
 
+async function loadSqlite(): Promise<typeof import('expo-sqlite')> {
+  return import('expo-sqlite');
+}
+
 export async function getDatabase(): Promise<SQLiteDatabase> {
   if (database) return database;
 
+  const SQLite = await loadSqlite();
   const db = await SQLite.openDatabaseAsync(DATABASE_NAME);
   await migrateDatabase(db);
   database = db;

mobile/services/db/id.ts

@@ -1,7 +1,7 @@
-import { getDatabase } from './client';
+import { getSession } from './session';
 
 export async function newResourceId(): Promise<string> {
-  const db = await getDatabase();
+  const db = await getSession();
   const row = await db.getFirstAsync<{ id: string }>(
     'SELECT lower(hex(randomblob(16))) AS id',
   );

mobile/services/db/migrations.ts

@@ -210,6 +210,8 @@ CREATE INDEX IF NOT EXISTS idx_folders_resource_id ON folders(resource_id);
 CREATE INDEX IF NOT EXISTS idx_files_resource_id ON files(resource_id);
 CREATE INDEX IF NOT EXISTS idx_files_folder_resource ON files(folder_resource_id);
 CREATE INDEX IF NOT EXISTS idx_folders_parent ON folders(parent_resource_id);
+CREATE UNIQUE INDEX IF NOT EXISTS idx_folders_uri ON folders(uri) WHERE uri IS NOT NULL;
+CREATE UNIQUE INDEX IF NOT EXISTS idx_files_uri ON files(uri) WHERE uri IS NOT NULL;
 `);
         await txn.execAsync(`PRAGMA user_version = 4;`);
       });

mobile/services/db/repositories/files.ts

@@ -1,4 +1,4 @@
-import { getDatabase } from '../client';
+import { getSession } from '../session';
 import { newResourceId } from '../id';
 import { FILE_COLUMNS_SQL } from '../schema';
 import { getDeviceUserId } from './preferences';
@@ -6,6 +6,7 @@ import type { FileEntry, FileRow, StoredFile, SyncStatus } from '../types';
 
 export type SaveFileOptions = {
   syncStatus?: SyncStatus;
+  resource_id?: string;
 };
 
 export async function saveFile(
@@ -13,15 +14,20 @@ export async function saveFile(
   folderResourceId: string,
   options: SaveFileOptions = {},
 ): Promise<StoredFile> {
-  const db = await getDatabase();
+  const db = await getSession();
   const now = Date.now();
   const exists = file.exists ? 1 : 0;
   const ownerId = await getDeviceUserId();
 
-  const existing = await db.getFirstAsync<FileRow>(
-    `SELECT ${FILE_COLUMNS_SQL} FROM files WHERE uri = ?`,
-    file.uri,
-  );
+  const existing = options.resource_id
+    ? await db.getFirstAsync<FileRow>(
+        `SELECT ${FILE_COLUMNS_SQL} FROM files WHERE resource_id = ?`,
+        options.resource_id,
+      )
+    : await db.getFirstAsync<FileRow>(
+        `SELECT ${FILE_COLUMNS_SQL} FROM files WHERE uri = ?`,
+        file.uri,
+      );
 
   const resourceId = existing?.resource_id ?? (await newResourceId());
   const baseSync = existing?.sync_status ?? options.syncStatus ?? 'local';
@@ -64,7 +70,7 @@ export async function saveFile(
 }
 
 export async function getFiles(folderResourceId?: string): Promise<StoredFile[]> {
-  const db = await getDatabase();
+  const db = await getSession();
   const rows =
     folderResourceId === undefined
       ? await db.getAllAsync<FileRow>(`SELECT ${FILE_COLUMNS_SQL} FROM files ORDER BY name ASC`)
@@ -76,7 +82,7 @@ export async function getFiles(folderResourceId?: string): Promise<StoredFile[]>
 }
 
 export async function getFile(resourceId: string): Promise<StoredFile | null> {
-  const db = await getDatabase();
+  const db = await getSession();
   const row = await db.getFirstAsync<FileRow>(
     `SELECT ${FILE_COLUMNS_SQL} FROM files WHERE resource_id = ?`,
     resourceId,
@@ -85,7 +91,7 @@ export async function getFile(resourceId: string): Promise<StoredFile | null> {
 }
 
 export async function removeFile(resourceId: string): Promise<void> {
-  const db = await getDatabase();
+  const db = await getSession();
   await db.runAsync('DELETE FROM files WHERE resource_id = ?', resourceId);
 }
 

mobile/services/db/repositories/folders.ts

@@ -1,4 +1,4 @@
-import { getDatabase } from '../client';
+import { getSession } from '../session';
 import { newResourceId } from '../id';
 import { FOLDER_COLUMNS_SQL } from '../schema';
 import { getDeviceUserId } from './preferences';
@@ -20,21 +20,21 @@ export async function saveFolder(
   input: SaveFolderInput,
   options: SaveFolderOptions = {},
 ): Promise<StoredFolder> {
-  const db = await getDatabase();
+  const db = await getSession();
   const now = Date.now();
   const exists =
     input.exists === undefined || input.exists === null ? null : input.exists ? 1 : 0;
   const ownerId = await getDeviceUserId();
 
-  const existing = input.uri
+  const existing = input.resource_id
     ? await db.getFirstAsync<FolderRow>(
-        `SELECT ${FOLDER_COLUMNS_SQL} FROM folders WHERE uri = ?`,
-        input.uri,
+        `SELECT ${FOLDER_COLUMNS_SQL} FROM folders WHERE resource_id = ?`,
+        input.resource_id,
       )
-    : input.resource_id
+    : input.uri
       ? await db.getFirstAsync<FolderRow>(
-          `SELECT ${FOLDER_COLUMNS_SQL} FROM folders WHERE resource_id = ?`,
-          input.resource_id,
+          `SELECT ${FOLDER_COLUMNS_SQL} FROM folders WHERE uri = ?`,
+          input.uri,
         )
       : null;
 
@@ -82,7 +82,7 @@ export async function saveDirectory(folder: {
 }
 
 export async function getFolders(): Promise<StoredFolder[]> {
-  const db = await getDatabase();
+  const db = await getSession();
   const rows = await db.getAllAsync<FolderRow>(
     `SELECT ${FOLDER_COLUMNS_SQL} FROM folders ORDER BY name ASC`,
   );
@@ -92,7 +92,7 @@ export async function getFolders(): Promise<StoredFolder[]> {
 export async function getFolderFolders(
   parentResourceId: string | null,
 ): Promise<StoredFolder[]> {
-  const db = await getDatabase();
+  const db = await getSession();
   const rows = await db.getAllAsync<FolderRow>(
     `SELECT ${FOLDER_COLUMNS_SQL} FROM folders WHERE parent_resource_id IS ? ORDER BY name ASC`,
     parentResourceId,
@@ -101,7 +101,7 @@ export async function getFolderFolders(
 }
 
 export async function getFolder(resourceId: string): Promise<StoredFolder | null> {
-  const db = await getDatabase();
+  const db = await getSession();
   const row = await db.getFirstAsync<FolderRow>(
     `SELECT ${FOLDER_COLUMNS_SQL} FROM folders WHERE resource_id = ?`,
     resourceId,
@@ -110,7 +110,7 @@ export async function getFolder(resourceId: string): Promise<StoredFolder | null
 }
 
 export async function removeFolder(resourceId: string): Promise<void> {
-  const db = await getDatabase();
+  const db = await getSession();
   await db.runAsync('DELETE FROM folders WHERE resource_id = ?', resourceId);
 }
 

mobile/services/db/repositories/pendingOps.ts

@@ -1,4 +1,4 @@
-import { getDatabase } from '../client';
+import { getSession } from '../session';
 import type {
   NewPendingOperation,
   PendingOperation,
@@ -13,10 +13,12 @@ const PENDING_OPERATION_COLUMNS = `
 const MAX_BACKOFF_MS = 24 * 60 * 60 * 1000;
 const BASE_BACKOFF_MS = 30 * 1000;
 
+export const MAX_PENDING_ATTEMPTS = 5;
+
 export async function enqueuePendingOperation(
   operation: NewPendingOperation,
 ): Promise<number> {
-  const db = await getDatabase();
+  const db = await getSession();
   const row = await db.getFirstAsync<{ id: number }>(
     `INSERT INTO pending_operations
        (resource_id, resource_type, ref_type, ref_id, operation, payload, status, attempts, created_at)
@@ -36,7 +38,7 @@ export async function enqueuePendingOperation(
 export async function getPendingOperations(
   status?: PendingOperationStatus,
 ): Promise<PendingOperation[]> {
-  const db = await getDatabase();
+  const db = await getSession();
   const rows = status
     ? await db.getAllAsync<PendingOperationRow>(
         `SELECT ${PENDING_OPERATION_COLUMNS} FROM pending_operations
@@ -51,7 +53,7 @@ export async function getPendingOperations(
 }
 
 export async function getNextQueuedOperation(): Promise<PendingOperation | null> {
-  const db = await getDatabase();
+  const db = await getSession();
   const row = await db.getFirstAsync<PendingOperationRow>(
     `SELECT ${PENDING_OPERATION_COLUMNS} FROM pending_operations
      WHERE status = 'pending'
@@ -68,7 +70,7 @@ export async function markPendingOperation(
   status: PendingOperationStatus,
   error?: string | null,
 ): Promise<void> {
-  const db = await getDatabase();
+  const db = await getSession();
   const now = Date.now();
 
   if (status === 'failed') {
@@ -78,12 +80,23 @@ export async function markPendingOperation(
     );
     if (!current) return;
     const attempts = current.attempts + 1;
+    if (attempts >= MAX_PENDING_ATTEMPTS) {
+      await db.runAsync(
+        `UPDATE pending_operations SET
+           status = 'failed', attempts = ?, error = ?, next_retry_at = NULL, last_error_at = ?
+         WHERE id = ?`,
+        attempts,
+        error ?? null,
+        now,
+        id,
+      );
+      return;
+    }
     const backoff = Math.min(BASE_BACKOFF_MS * 2 ** attempts, MAX_BACKOFF_MS);
     await db.runAsync(
       `UPDATE pending_operations SET
-         status = ?, attempts = ?, error = ?, next_retry_at = ?, last_error_at = ?
+         status = 'pending', attempts = ?, error = ?, next_retry_at = ?, last_error_at = ?
        WHERE id = ?`,
-      status,
       attempts,
       error ?? null,
       now + backoff,

mobile/services/db/repositories/permissions.ts

@@ -1,5 +1,5 @@
-import type { SQLiteDatabase } from 'expo-sqlite';
-import { getDatabase } from '../client';
+import type { DbSession } from '../session';
+import { getSession } from '../session';
 import { PERMISSION_TTL_MS } from '../schema';
 import { getDeviceUserId } from './preferences';
 import type {
@@ -29,6 +29,7 @@ export type AccessCheck = {
 
 type LineageNode = {
   resource_id: string;
+  resource_type: ResourceType;
   parent_resource_id: string | null;
   owner_id: string;
 };
@@ -41,7 +42,7 @@ export async function getResourcePermission(
   resourceId: string,
   resourceType: ResourceType,
 ): Promise<ResourcePermission | null> {
-  const db = await getDatabase();
+  const db = await getSession();
   const row = await db.getFirstAsync<ResourcePermissionRow>(
     `SELECT * FROM resource_permissions WHERE resource_id = ? AND resource_type = ?`,
     resourceId,
@@ -53,7 +54,7 @@ export async function getResourcePermission(
 export async function saveResourcePermission(
   permission: NewResourcePermission,
 ): Promise<void> {
-  const db = await getDatabase();
+  const db = await getSession();
   const now = Date.now();
   await db.runAsync(
     `INSERT INTO resource_permissions
@@ -83,21 +84,32 @@ async function resourceLineage(
   resourceId: string,
   resourceType: ResourceType,
 ): Promise<LineageNode[]> {
-  const db = await getDatabase();
+  const db = await getSession();
 
-  const anchor = await db.getFirstAsync<{ folder_resource_id: string }>(
-    'SELECT folder_resource_id FROM files WHERE resource_id = ?',
-    resourceId,
-  );
   if (resourceType === 'file') {
-    if (!anchor) return [];
-    return folderLineage(db, anchor.folder_resource_id);
+    const file = await db.getFirstAsync<{
+      folder_resource_id: string;
+      owner_id: string;
+    }>(
+      'SELECT folder_resource_id, owner_id FROM files WHERE resource_id = ?',
+      resourceId,
+    );
+    if (!file) return [];
+    return [
+      {
+        resource_id: resourceId,
+        resource_type: 'file',
+        parent_resource_id: file.folder_resource_id,
+        owner_id: file.owner_id,
+      },
+      ...(await folderLineage(db, file.folder_resource_id)),
+    ];
   }
   return folderLineage(db, resourceId);
 }
 
 async function folderLineage(
-  db: SQLiteDatabase,
+  db: DbSession,
   startResourceId: string,
 ): Promise<LineageNode[]> {
   const rows = await db.getAllAsync<LineageNode>(
@@ -108,34 +120,18 @@ async function folderLineage(
        FROM folders f
        JOIN lineage l ON f.resource_id = l.parent_resource_id
      )
-     SELECT resource_id, parent_resource_id, owner_id FROM lineage`,
+     SELECT resource_id, 'folder' AS resource_type, parent_resource_id, owner_id FROM lineage`,
     startResourceId,
   );
   return rows;
 }
 
-function decideFromPermission(
-  permission: ResourcePermission,
-  required: AccessLevel,
-  now: number,
-): AccessCheck {
-  if (permission.expiresAt != null && permission.expiresAt < now) {
-    return {
-      allowed: false,
-      access: permission.effectiveAccess,
-      source: 'cache',
-      stale: false,
-      expiresAt: permission.expiresAt,
-    };
-  }
-  const granted = rank(permission.effectiveAccess) >= rank(required);
-  return {
-    allowed: granted,
-    access: permission.effectiveAccess,
-    source: 'cache',
-    stale: now - permission.cachedAt > PERMISSION_TTL_MS,
-    expiresAt: permission.expiresAt,
-  };
+function isStale(cachedAt: number, now: number): boolean {
+  return now - cachedAt > PERMISSION_TTL_MS;
+}
+
+function readOnlyAccess(permission: ResourcePermission, now: number): AccessLevel {
+  return isStale(permission.cachedAt, now) ? 'viewer' : permission.effectiveAccess;
 }
 
 export async function canAccess(
@@ -143,28 +139,75 @@ export async function canAccess(
   resourceType: ResourceType,
   required: AccessLevel,
 ): Promise<AccessCheck> {
-  const db = await getDatabase();
   const now = Date.now();
   const deviceUserId = await getDeviceUserId();
 
-  const cached = await getResourcePermission(resourceId, resourceType);
-  if (cached) return decideFromPermission(cached, required, now);
+  const exactCache = await getResourcePermission(resourceId, resourceType);
+  if (exactCache) {
+    if (exactCache.expiresAt != null && exactCache.expiresAt < now) {
+      return {
+        allowed: false,
+        access: exactCache.effectiveAccess,
+        source: 'cache',
+        stale: false,
+        expiresAt: exactCache.expiresAt,
+      };
+    }
+    const stale = isStale(exactCache.cachedAt, now);
+    const applyAccess = readOnlyAccess(exactCache, now);
+    return {
+      allowed: rank(applyAccess) >= rank(required),
+      access: applyAccess,
+      source: 'cache',
+      stale,
+      expiresAt: exactCache.expiresAt,
+    };
+  }
 
   const lineage = await resourceLineage(resourceId, resourceType);
-  for (const node of lineage) {
+  let best: {
+    access: AccessLevel;
+    source: AccessSource;
+    stale: boolean;
+    expiresAt: number | null;
+  } | null = null;
+
+  for (const [index, node] of lineage.entries()) {
     if (node.owner_id === deviceUserId) {
       return { allowed: true, access: 'owner', source: 'owner', stale: false, expiresAt: null };
     }
-    const nodePermission = await getResourcePermission(node.resource_id, 'folder');
-    if (nodePermission) {
-      const decision = decideFromPermission(nodePermission, required, now);
-      if (decision.source === 'cache') {
-        return { ...decision, source: 'inherited' };
-      }
+
+    const nodePermission = await getResourcePermission(node.resource_id, node.resource_type);
+    if (!nodePermission) continue;
+    if (nodePermission.expiresAt != null && nodePermission.expiresAt < now) continue;
+    if (index > 0 && nodePermission.inherit === false) continue;
+
+    const stale = isStale(nodePermission.cachedAt, now);
+    const candidate = {
+      access: readOnlyAccess(nodePermission, now),
+      source: (index === 0 ? 'cache' : 'inherited') as AccessSource,
+      stale,
+      expiresAt: nodePermission.expiresAt,
+    };
+    if (
+      !best ||
+      rank(candidate.access) > rank(best.access) ||
+      (rank(candidate.access) === rank(best.access) && !candidate.stale && best.stale)
+    ) {
+      best = candidate;
     }
   }
 
-  return { allowed: false, access: null, source: 'none', stale: false, expiresAt: null };
+  if (!best) {
+    return { allowed: false, access: null, source: 'none', stale: false, expiresAt: null };
+  }
+  return {
+    allowed: rank(best.access) >= rank(required),
+    access: best.access,
+    source: best.source,
+    stale: best.stale,
+    expiresAt: best.expiresAt,
+  };
 }
 
 export async function canWrite(

mobile/services/db/repositories/preferences.ts

@@ -1,4 +1,4 @@
-import { getDatabase } from '../client';
+import { getSession } from '../session';
 import { DEVICE_USER_ID_KEY, PREFERENCES_KEY } from '../schema';
 import type { UserPreferences } from '../types';
 
@@ -7,7 +7,7 @@ const DEFAULT_PREFERENCES: UserPreferences = {
 };
 
 export async function getDeviceUserId(): Promise<string> {
-  const db = await getDatabase();
+  const db = await getSession();
   const row = await db.getFirstAsync<{ value: string }>(
     'SELECT "value" FROM user_preferences WHERE "key" = ?',
     DEVICE_USER_ID_KEY,
@@ -28,7 +28,7 @@ export async function getDeviceUserId(): Promise<string> {
 }
 
 export async function saveUserPreferences(preferences: UserPreferences): Promise<void> {
-  const db = await getDatabase();
+  const db = await getSession();
   await db.runAsync(
     `INSERT INTO user_preferences ("key", "value", updated_at) VALUES (?, ?, ?)
      ON CONFLICT("key") DO UPDATE SET "value" = excluded."value", updated_at = excluded.updated_at`,
@@ -39,7 +39,7 @@ export async function saveUserPreferences(preferences: UserPreferences): Promise
 }
 
 export async function getUserPreferences(): Promise<UserPreferences> {
-  const db = await getDatabase();
+  const db = await getSession();
   const row = await db.getFirstAsync<{ value: string }>(
     'SELECT "value" FROM user_preferences WHERE "key" = ?',
     PREFERENCES_KEY,

mobile/services/db/repositories/recipients.ts

@@ -1,4 +1,4 @@
-import { getDatabase } from '../client';
+import { getSession } from '../session';
 import type { Recipient, RecipientRow, RecipientType } from '../types';
 
 export async function saveRecipient(
@@ -6,7 +6,7 @@ export async function saveRecipient(
   recipientId: string,
   displayName: string,
 ): Promise<Recipient> {
-  const db = await getDatabase();
+  const db = await getSession();
   await db.runAsync(
     `INSERT INTO recipients (recipient_type, recipient_id, display_name, is_active, updated_at)
      VALUES (?, ?, ?, 1, ?)
@@ -28,7 +28,7 @@ export async function saveRecipient(
 }
 
 export async function getRecipients(activeOnly = true): Promise<Recipient[]> {
-  const db = await getDatabase();
+  const db = await getSession();
   const rows = activeOnly
     ? await db.getAllAsync<RecipientRow>(
         'SELECT * FROM recipients WHERE is_active = 1 ORDER BY display_name ASC',
@@ -42,7 +42,7 @@ export async function setRecipientActive(
   recipientId: string,
   active: boolean,
 ): Promise<void> {
-  const db = await getDatabase();
+  const db = await getSession();
   await db.runAsync(
     `UPDATE recipients SET is_active = ?, updated_at = ?
      WHERE recipient_type = ? AND recipient_id = ?`,

mobile/services/db/repositories/shareLinks.ts

@@ -1,4 +1,4 @@
-import { getDatabase } from '../client';
+import { getSession } from '../session';
 import type { NewShareLink, ResourceType, ShareLink, ShareLinkRow } from '../types';
 
 const PUSH_STATUS_SQL = `(
@@ -16,7 +16,7 @@ const PUSH_STATUS_SQL = `(
 ) AS push_status`;
 
 export async function createShareLink(input: NewShareLink): Promise<ShareLink> {
-  const db = await getDatabase();
+  const db = await getSession();
   const now = Date.now();
 
   let token = input.token;
@@ -49,7 +49,7 @@ export async function createShareLink(input: NewShareLink): Promise<ShareLink> {
 }
 
 export async function getShareLinkById(id: number): Promise<ShareLink | null> {
-  const db = await getDatabase();
+  const db = await getSession();
   const row = await db.getFirstAsync<ShareLinkRow & { push_status: ShareLink['pushStatus'] }>(
     `SELECT sl.*, ${PUSH_STATUS_SQL} FROM share_links sl WHERE sl.id = ?`,
     id,
@@ -58,7 +58,7 @@ export async function getShareLinkById(id: number): Promise<ShareLink | null> {
 }
 
 export async function getShareLinkByToken(token: string): Promise<ShareLink | null> {
-  const db = await getDatabase();
+  const db = await getSession();
   const row = await db.getFirstAsync<ShareLinkRow & { push_status: ShareLink['pushStatus'] }>(
     `SELECT sl.*, ${PUSH_STATUS_SQL} FROM share_links sl WHERE sl.token = ?`,
     token,
@@ -70,7 +70,7 @@ export async function getShareLinks(
   resourceId?: string,
   resourceType?: ResourceType,
 ): Promise<ShareLink[]> {
-  const db = await getDatabase();
+  const db = await getSession();
   let sql = `SELECT sl.*, ${PUSH_STATUS_SQL} FROM share_links sl`;
   const params: string[] = [];
   if (resourceId) {
@@ -87,7 +87,7 @@ export async function getShareLinks(
 }
 
 export async function incrementLinkDownloads(id: number): Promise<void> {
-  const db = await getDatabase();
+  const db = await getSession();
   await db.runAsync(
     `UPDATE share_links SET downloads_count = downloads_count + 1, updated_at = ? WHERE id = ?`,
     Date.now(),
@@ -96,7 +96,7 @@ export async function incrementLinkDownloads(id: number): Promise<void> {
 }
 
 export async function revokeShareLink(id: number): Promise<void> {
-  const db = await getDatabase();
+  const db = await getSession();
   await db.runAsync(
     `UPDATE share_links SET is_revoked = 1, updated_at = ? WHERE id = ?`,
     Date.now(),
@@ -108,7 +108,7 @@ export async function removeShareLinksForResource(
   resourceId: string,
   resourceType: ResourceType,
 ): Promise<void> {
-  const db = await getDatabase();
+  const db = await getSession();
   await db.runAsync('DELETE FROM share_links WHERE resource_id = ? AND resource_type = ?', resourceId, resourceType);
 }
 

mobile/services/db/repositories/shares.ts

@@ -1,4 +1,4 @@
-import { getDatabase } from '../client';
+import { getSession } from '../session';
 import type { NewShare, ResourceType, Share, ShareRow } from '../types';
 
 const PUSH_STATUS_SQL = `(
@@ -16,7 +16,7 @@ const PUSH_STATUS_SQL = `(
 ) AS push_status`;
 
 export async function saveShare(share: NewShare): Promise<Share> {
-  const db = await getDatabase();
+  const db = await getSession();
   const now = Date.now();
 
   await db.runAsync(
@@ -56,7 +56,7 @@ export async function getShare(
   recipientType: 'user' | 'group',
   recipientId: string,
 ): Promise<Share | null> {
-  const db = await getDatabase();
+  const db = await getSession();
   const row = await db.getFirstAsync<ShareRow & { push_status: Share['pushStatus'] }>(
     `SELECT s.*, ${PUSH_STATUS_SQL} FROM shares s
      WHERE s.resource_id = ? AND s.resource_type = ? AND s.recipient_type = ? AND s.recipient_id = ?`,
@@ -72,7 +72,7 @@ export async function getShares(
   resourceId?: string,
   resourceType?: ResourceType,
 ): Promise<Share[]> {
-  const db = await getDatabase();
+  const db = await getSession();
   let sql = `SELECT s.*, ${PUSH_STATUS_SQL} FROM shares s`;
   const params: string[] = [];
   if (resourceId) {
@@ -94,7 +94,7 @@ export async function removeShare(
   recipientType: 'user' | 'group',
   recipientId: string,
 ): Promise<void> {
-  const db = await getDatabase();
+  const db = await getSession();
   await db.runAsync(
     `DELETE FROM shares
      WHERE resource_id = ? AND resource_type = ? AND recipient_type = ? AND recipient_id = ?`,
@@ -109,7 +109,7 @@ export async function removeSharesForResource(
   resourceId: string,
   resourceType: ResourceType,
 ): Promise<void> {
-  const db = await getDatabase();
+  const db = await getSession();
   await db.runAsync('DELETE FROM shares WHERE resource_id = ? AND resource_type = ?', resourceId, resourceType);
 }
 

mobile/services/db/session.ts

@@ -0,0 +1,18 @@
+import { getDatabase } from './client';
+import type { SQLiteBindValue } from 'expo-sqlite';
+
+export type DbSession = {
+  runAsync(sql: string, ...params: SQLiteBindValue[]): Promise<unknown>;
+  getFirstAsync<T>(sql: string, ...params: SQLiteBindValue[]): Promise<T | null>;
+  getAllAsync<T>(sql: string, ...params: SQLiteBindValue[]): Promise<T[]>;
+};
+
+let override: DbSession | null = null;
+
+export function __setDbForTests(db: DbSession | null): void {
+  override = db;
+}
+
+export async function getSession(): Promise<DbSession> {
+  return override ?? (await getDatabase());
+}

mobile/tests/repositories.test.ts

@@ -0,0 +1,442 @@
+import { test, beforeEach, afterEach } from 'node:test';
+import assert from 'node:assert/strict';
+import Database from 'better-sqlite3';
+import { MIGRATIONS, type MigrationDb } from '../services/db/migrations';
+import type { DbSession } from '../services/db/session';
+import { __setDbForTests } from '../services/db/session';
+import {
+  saveFolder,
+  getFolders,
+  getFolder,
+  removeFolder,
+  saveFile,
+  getFiles,
+  canAccess,
+  saveResourcePermission,
+  saveShare,
+  getShares,
+  createShareLink,
+  getShareLinks,
+  incrementLinkDownloads,
+  enqueuePendingOperation,
+  getPendingOperations,
+  getNextQueuedOperation,
+  markPendingOperation,
+  getDeviceUserId,
+  DEVICE_USER_ID_KEY,
+  PERMISSION_TTL_MS,
+} from '../services/db';
+import type { FileEntry } from '../services/safDirectory.types';
+import { MAX_PENDING_ATTEMPTS } from '../services/db/repositories/pendingOps';
+
+type Harness = MigrationDb & DbSession;
+
+let h: Harness;
+
+function createHarness(): Harness {
+  const sqlite = new Database(':memory:');
+  const harness: Harness = {
+    execAsync: async (sql: string) => {
+      sqlite.exec(sql);
+    },
+    runAsync: async (sql: string, ...params: unknown[]) => {
+      sqlite.prepare(sql).run(...params);
+    },
+    getFirstAsync: async (sql: string, ...params: unknown[]) =>
+      (sqlite.prepare(sql).get(...params) ?? null) as never,
+    getAllAsync: async (sql: string, ...params: unknown[]) =>
+      sqlite.prepare(sql).all(...params) as never,
+    withExclusiveTransactionAsync: async (task: (txn: Harness) => Promise<void>) => {
+      sqlite.exec('BEGIN');
+      try {
+        await task(harness);
+        sqlite.exec('COMMIT');
+      } catch (error) {
+        sqlite.exec('ROLLBACK');
+        throw error;
+      }
+    },
+  };
+  return harness;
+}
+
+beforeEach(async () => {
+  h = createHarness();
+  for (const migration of MIGRATIONS) {
+    await migration.up(h);
+  }
+  __setDbForTests(h);
+});
+
+afterEach(() => {
+  __setDbForTests(null);
+});
+
+function fileEntry(uri: string, overrides: Partial<FileEntry> = {}): FileEntry {
+  return {
+    uri,
+    name: uri.split('/').pop() ?? uri,
+    isDirectory: false,
+    extension: uri.split('.').pop() ?? '',
+    exists: true,
+    size: 10,
+    type: 'application/octet-stream',
+    lastModified: 1,
+    ...overrides,
+  };
+}
+
+async function setOwner(
+  table: 'folders' | 'files',
+  resourceId: string,
+  ownerId: string,
+): Promise<void> {
+  await h.runAsync(`UPDATE ${table} SET owner_id = ? WHERE resource_id = ?`, ownerId, resourceId);
+}
+
+test('folder upsert is idempotent by uri (same resource_id, single row)', async () => {
+  const a = await saveFolder({ uri: 'content://a', name: 'A' });
+  const b = await saveFolder({ uri: 'content://a', name: 'A renamed' });
+
+  assert.equal(a.resource_id, b.resource_id);
+  assert.equal(b.name, 'A renamed');
+  assert.equal(b.uri, 'content://a');
+  assert.equal((await getFolders()).length, 1);
+});
+
+test('distinct uris produce distinct rows', async () => {
+  await saveFolder({ uri: 'content://a', name: 'A' });
+  await saveFolder({ uri: 'content://b', name: 'B' });
+  assert.equal((await getFolders()).length, 2);
+});
+
+test('cloud-only folder gains a uri without duplicating (reconciled by resource_id)', async () => {
+  const cloud = await saveFolder({ uri: null, name: 'Cloud', resource_id: 'abc123' });
+  assert.equal(cloud.uri, null);
+  const wired = await saveFolder({ uri: 'content://cloud', name: 'Cloud', resource_id: 'abc123' });
+  assert.equal(wired.resource_id, 'abc123');
+  assert.equal(wired.uri, 'content://cloud');
+  assert.equal((await getFolders()).length, 1);
+});
+
+test('inserting a folder with a nonexistent parent throws a FK error (no silent orphan)', async () => {
+  await assert.rejects(
+    () => saveFolder({ uri: 'content://child', name: 'C' }, { parentResourceId: 'does-not-exist' }),
+    /FOREIGN KEY/,
+  );
+});
+
+test('inserting a file before its parent folder throws a FK error', async () => {
+  await assert.rejects(
+    () => saveFile(fileEntry('content://orphan/f.pdf'), 'missing-folder'),
+    /FOREIGN KEY/,
+  );
+});
+
+test('re-saving a folder without a parent keeps the existing parent', async () => {
+  const root = await saveFolder({ uri: 'content://r', name: 'R' });
+  const child = await saveFolder({ uri: 'content://r/c', name: 'C' }, { parentResourceId: root.resource_id });
+  const reSaved = await saveFolder({ uri: 'content://r/c', name: 'C2' });
+  assert.equal(reSaved.parent_resource_id, root.resource_id);
+});
+
+test('a full SAF walk repeated twice is a no-op (BFS order, uri reconciliation)', async () => {
+  const root = await saveFolder({ uri: 'content://root', name: 'Root' });
+  const sub = await saveFolder({ uri: 'content://root/sub', name: 'Sub' }, { parentResourceId: root.resource_id });
+  await saveFile(fileEntry('content://root/sub/f1.pdf'), sub.resource_id);
+
+  const root2 = await saveFolder({ uri: 'content://root', name: 'Root' });
+  const sub2 = await saveFolder({ uri: 'content://root/sub', name: 'Sub' }, { parentResourceId: root2.resource_id });
+  await saveFile(fileEntry('content://root/sub/f1.pdf'), sub2.resource_id);
+
+  assert.equal(root.resource_id, root2.resource_id);
+  assert.equal(sub.resource_id, sub2.resource_id);
+  assert.equal(sub2.parent_resource_id, root2.resource_id);
+  assert.equal((await getFolders()).length, 2);
+  assert.equal((await getFiles()).length, 1);
+  const stored = await getFiles(sub2.resource_id);
+  assert.equal(stored.length, 1);
+});
+
+test('removing a root folder cascades to its subtree and files', async () => {
+  const root = await saveFolder({ uri: 'content://root', name: 'Root' });
+  const sub = await saveFolder({ uri: 'content://root/sub', name: 'Sub' }, { parentResourceId: root.resource_id });
+  await saveFile(fileEntry('content://root/sub/f1.pdf'), sub.resource_id);
+
+  await removeFolder(root.resource_id);
+
+  assert.equal((await getFolders()).length, 0);
+  assert.equal((await getFiles()).length, 0);
+});
+
+test('canAccess: nothing granted => denied, owner fallback grants owner', async () => {
+  const root = await saveFolder({ uri: 'content://r', name: 'R' });
+  const sub = await saveFolder({ uri: 'content://r/s', name: 'S' }, { parentResourceId: root.resource_id });
+  const f = await saveFile(fileEntry('content://r/s/f.pdf'), sub.resource_id);
+
+  const device = await getDeviceUserId();
+  await setOwner('folders', root.resource_id, 'other');
+  await setOwner('folders', sub.resource_id, 'other');
+  await setOwner('files', f.resource_id, 'other');
+
+  assert.equal((await canAccess(f.resource_id, 'file', 'viewer')).allowed, false);
+  assert.equal((await canAccess(sub.resource_id, 'folder', 'viewer')).allowed, false);
+
+  await setOwner('folders', sub.resource_id, device);
+  assert.equal((await canAccess(f.resource_id, 'file', 'owner')).allowed, true);
+  assert.equal((await canAccess(f.resource_id, 'file', 'viewer')).source, 'owner');
+});
+
+test('canAccess: granted permission on an ancestor inherits through deep folders', async () => {
+  const ids: string[] = [];
+  let parentResourceId: string | null = null;
+  for (let depth = 0; depth < 5; depth++) {
+    const folder = await saveFolder(
+      { uri: `content://chain/${depth}`, name: `n${depth}` },
+      { parentResourceId },
+    );
+    ids.push(folder.resource_id);
+    parentResourceId = folder.resource_id;
+  }
+  const f = await saveFile(fileEntry('content://chain/f.pdf'), parentResourceId!);
+  const device = await getDeviceUserId();
+  for (const id of ids) await setOwner('folders', id, 'other');
+  await setOwner('files', f.resource_id, 'other');
+
+  await saveResourcePermission({
+    resource_id: ids[0],
+    resourceType: 'folder',
+    effectiveAccess: 'viewer',
+    inherit: true,
+  });
+  assert.equal((await canAccess(f.resource_id, 'file', 'viewer')).allowed, true, 'viewer inherited from root');
+  assert.equal((await canAccess(f.resource_id, 'file', 'editor')).allowed, false, 'viewer is not editor');
+  assert.equal((await canAccess(f.resource_id, 'file', 'viewer')).source, 'inherited');
+});
+
+test('canAccess: inherit=false blocks propagation but allows the node itself', async () => {
+  const root = await saveFolder({ uri: 'content://r', name: 'R' });
+  const sub = await saveFolder({ uri: 'content://r/s', name: 'S' }, { parentResourceId: root.resource_id });
+  const f = await saveFile(fileEntry('content://r/s/f.pdf'), sub.resource_id);
+  const device = await getDeviceUserId();
+  await setOwner('folders', root.resource_id, 'other');
+  await setOwner('folders', sub.resource_id, 'other');
+  await setOwner('files', f.resource_id, 'other');
+
+  await saveResourcePermission({
+    resource_id: root.resource_id,
+    resourceType: 'folder',
+    effectiveAccess: 'viewer',
+    inherit: false,
+  });
+  assert.equal((await canAccess(root.resource_id, 'folder', 'viewer')).allowed, true, 'root itself keeps viewer');
+  assert.equal((await canAccess(sub.resource_id, 'folder', 'viewer')).allowed, false, 'inheritance stopped');
+  assert.equal((await canAccess(f.resource_id, 'file', 'viewer')).allowed, false);
+
+  await saveResourcePermission({
+    resource_id: sub.resource_id,
+    resourceType: 'folder',
+    effectiveAccess: 'viewer',
+    inherit: true,
+  });
+  assert.equal((await canAccess(f.resource_id, 'file', 'viewer')).allowed, true, 'closer ancestor grants descend');
+});
+
+test('canAccess: an expired permission is denied and does not propagate', async () => {
+  const root = await saveFolder({ uri: 'content://r', name: 'R' });
+  const sub = await saveFolder({ uri: 'content://r/s', name: 'S' }, { parentResourceId: root.resource_id });
+  const device = await getDeviceUserId();
+  await setOwner('folders', root.resource_id, 'other');
+  await setOwner('folders', sub.resource_id, 'other');
+
+  await saveResourcePermission({
+    resource_id: root.resource_id,
+    resourceType: 'folder',
+    effectiveAccess: 'viewer',
+    inherit: true,
+    expiresAt: Date.now() - 1000,
+  });
+  assert.equal((await canAccess(root.resource_id, 'folder', 'viewer')).allowed, false);
+  assert.equal((await canAccess(sub.resource_id, 'folder', 'viewer')).allowed, false);
+});
+
+test('canAccess: stale cache only allows read (viewer), fresh cache allows the granted level', async () => {
+  const root = await saveFolder({ uri: 'content://r', name: 'R' });
+  const sub = await saveFolder({ uri: 'content://r/s', name: 'S' }, { parentResourceId: root.resource_id });
+  const device = await getDeviceUserId();
+  await setOwner('folders', root.resource_id, 'other');
+  await setOwner('folders', sub.resource_id, 'other');
+
+  await saveResourcePermission({
+    resource_id: root.resource_id,
+    resourceType: 'folder',
+    effectiveAccess: 'editor',
+    inherit: true,
+  });
+  assert.equal((await canAccess(sub.resource_id, 'folder', 'editor')).allowed, true, 'fresh editor grant');
+
+  await h.runAsync(
+    'UPDATE resource_permissions SET cached_at = ? WHERE resource_id = ?',
+    Date.now() - PERMISSION_TTL_MS - 60_000,
+    root.resource_id,
+  );
+  assert.equal((await canAccess(sub.resource_id, 'folder', 'viewer')).allowed, true, 'stale still allows read');
+  assert.equal((await canAccess(sub.resource_id, 'folder', 'editor')).allowed, false, 'stale blocks writes');
+  assert.equal((await canAccess(sub.resource_id, 'folder', 'viewer')).stale, true);
+});
+
+test('canAccess: a cached decision on the exact node is authoritative even if weaker', async () => {
+  const root = await saveFolder({ uri: 'content://r', name: 'R' });
+  const sub = await saveFolder({ uri: 'content://r/s', name: 'S' }, { parentResourceId: root.resource_id });
+  const device = await getDeviceUserId();
+  await setOwner('folders', root.resource_id, 'other');
+  await setOwner('folders', sub.resource_id, 'other');
+
+  await saveResourcePermission({
+    resource_id: root.resource_id,
+    resourceType: 'folder',
+    effectiveAccess: 'editor',
+    inherit: true,
+  });
+  await saveResourcePermission({
+    resource_id: sub.resource_id,
+    resourceType: 'folder',
+    effectiveAccess: 'viewer',
+    inherit: true,
+  });
+
+  assert.equal((await canAccess(sub.resource_id, 'folder', 'viewer')).allowed, true);
+  assert.equal((await canAccess(sub.resource_id, 'folder', 'editor')).allowed, false, 'exact viewer cache overrides inherited editor');
+});
+
+test('outbox: ops on the same resource are drained in FIFO order (id tie-break)', async () => {
+  const id1 = await enqueuePendingOperation({ operation: 'create_resource', resourceId: 'a' });
+  const id2 = await enqueuePendingOperation({ operation: 'update_metadata', resourceId: 'a' });
+  const id3 = await enqueuePendingOperation({ operation: 'delete_resource', resourceId: 'a' });
+  await h.runAsync('UPDATE pending_operations SET created_at = ?', 1000);
+
+  const ops = await getPendingOperations();
+  assert.deepEqual(
+    ops.map((o) => o.operation),
+    ['create_resource', 'update_metadata', 'delete_resource'],
+  );
+
+  const first = await getNextQueuedOperation();
+  assert.equal(first!.id, id1);
+  await markPendingOperation(first!.id, 'completed');
+  const second = await getNextQueuedOperation();
+  assert.equal(second!.id, id2);
+  await markPendingOperation(second!.id, 'completed');
+  assert.equal((await getNextQueuedOperation())!.id, id3);
+});
+
+test('outbox: a failure stays pending with a backoff, then dead-letters after max attempts', async () => {
+  const id = await enqueuePendingOperation({ operation: 'create_resource', resourceId: 'a' });
+
+  await markPendingOperation(id, 'failed', 'boom');
+  let row = await h.getFirstAsync<{
+    status: string;
+    attempts: number;
+    next_retry_at: number | null;
+  }>('SELECT status, attempts, next_retry_at FROM pending_operations WHERE id = ?', id);
+  assert.equal(row!.status, 'pending');
+  assert.equal(row!.attempts, 1);
+  assert.ok((row!.next_retry_at ?? 0) > Date.now(), 'retry scheduled in the future');
+
+  assert.equal(await getNextQueuedOperation(), null, 'backoff respects next_retry_at');
+
+  await h.runAsync('UPDATE pending_operations SET next_retry_at = ? WHERE id = ?', 0, id);
+  const due = await getNextQueuedOperation();
+  assert.ok(due);
+  assert.equal(due.attempts, 1);
+
+  for (let i = 0; i < MAX_PENDING_ATTEMPTS - 1; i++) {
+    await markPendingOperation(id, 'failed', 'still failing');
+  }
+  row = await h.getFirstAsync<{
+    status: string;
+    attempts: number;
+    next_retry_at: number | null;
+  }>('SELECT status, attempts, next_retry_at FROM pending_operations WHERE id = ?', id);
+  assert.equal(row!.status, 'failed', 'dead-lettered');
+  assert.equal(row!.attempts, MAX_PENDING_ATTEMPTS);
+  assert.equal(row!.next_retry_at, null);
+  assert.equal(await getNextQueuedOperation(), null, 'dead-lettered ops are never re-picked');
+
+  const share = await saveShare({
+    resourceId: 'a',
+    resourceType: 'folder',
+    recipientType: 'user',
+    recipientId: 'u1',
+    relation: 'viewer',
+  });
+  assert.equal(share.pushStatus, 'synced');
+});
+
+test('shares and share links derive pushStatus from the outbox', async () => {
+  const share = await saveShare({
+    resourceId: 'res-1',
+    resourceType: 'folder',
+    recipientType: 'user',
+    recipientId: 'u1',
+    relation: 'editor',
+  });
+  assert.equal(share.pushStatus, 'synced');
+
+  const opId = await enqueuePendingOperation({
+    refType: 'share',
+    refId: share.id,
+    operation: 'share',
+    resourceId: 'res-1',
+    resourceType: 'folder',
+  });
+  assert.equal((await getShares('res-1', 'folder'))[0].pushStatus, 'pending');
+
+  await markPendingOperation(opId, 'failed', 'nope');
+  assert.equal(
+    (await getShares('res-1', 'folder'))[0].pushStatus,
+    'pending',
+    'a single failure schedules a retry, share stays pending',
+  );
+
+  for (let attempt = 1; attempt < MAX_PENDING_ATTEMPTS; attempt++) {
+    await markPendingOperation(opId, 'failed', 'still failing');
+  }
+  assert.equal((await getShares('res-1', 'folder'))[0].pushStatus, 'failed', 'dead-lettered');
+
+  await markPendingOperation(opId, 'completed');
+  const shares = await getShares('res-1', 'folder');
+  assert.equal(shares.length, 1);
+  assert.equal(shares[0].pushStatus, 'synced', 'no pending/failed left');
+
+  const link = await createShareLink({ resourceId: 'res-1', resourceType: 'folder' });
+  assert.match(link.token, /^[0-9a-f]{32}$/);
+  assert.equal(link.pushStatus, 'synced');
+
+  const linkOpId = await enqueuePendingOperation({
+    refType: 'share_link',
+    refId: link.id,
+    operation: 'create_link',
+  });
+  assert.equal((await getShareLinks('res-1', 'folder'))[0].pushStatus, 'pending');
+  await markPendingOperation(linkOpId, 'completed');
+  assert.equal((await getShareLinks('res-1', 'folder'))[0].pushStatus, 'synced');
+
+  await incrementLinkDownloads(link.id);
+  assert.equal((await getShareLinks('res-1', 'folder'))[0].downloadsCount, 1);
+});
+
+test('device user id is a stable lowercase 32-hex string shared by all rows', async () => {
+  const device = await getDeviceUserId();
+  assert.match(device, /^[0-9a-f]{32}$/);
+
+  const root = await saveFolder({ uri: 'content://r', name: 'R' });
+  const rootRow = await getFolder(root.resource_id);
+  assert.equal(rootRow!.owner_id, device);
+
+  const seeded = await h.getFirstAsync<{ value: string }>(
+    'SELECT "value" FROM user_preferences WHERE "key" = ?',
+    DEVICE_USER_ID_KEY,
+  );
+  assert.equal(seeded!.value, device);
+});