Add notification system with admin UI and backend

Introduces a full notification system with support for Discord and Pushover backends, event triggers, and message formatting. Adds backend services, processors, and API endpoints for managing notifications, as well as a new Notifications tab in the admin settings UI. Updates documentation, database schema, and tests to cover notification features and approval workflow improvements. Also changes project license from MIT to AGPL v3.

documentation/phase3/qbittorrent.md

@@ -88,35 +88,54 @@ This prevents issues where category retains old save path after user changes `do
 **Use Case:** qBittorrent runs on different machine/container with different filesystem perspective.
 
 **Example Scenario:**
-- qBittorrent reports: `/remote/mnt/d/done/Audiobook.Name`
-- ReadMeABook needs: `/downloads/Audiobook.Name`
-- Mapping: Remote `/remote/mnt/d/done` → Local `/downloads`
+- qBittorrent on Windows expects: `F:\Docker\downloads\completed\books`
+- ReadMeABook inside Docker sees: `/downloads`
+- Mapping: Remote `F:\Docker\downloads\completed\books` ↔ Local `/downloads`
 
 **Configuration:**
 1. Admin Settings → Download Client → Enable Remote Path Mapping
-2. Enter remote path (as reported by qBittorrent)
-3. Enter local path (accessible to ReadMeABook)
+2. Enter remote path (as qBittorrent sees it, e.g., `F:\Docker\downloads\completed\books`)
+3. Enter local path (as RMAB sees it, e.g., `/downloads`)
 4. Test connection validates local path exists
 5. Save settings
 
+**Bidirectional Path Mapping:**
+
+**1. Outgoing (RMAB → qBittorrent):** When adding torrents
+- RMAB's download path: `/downloads`
+- Translated to qBit's path: `F:\Docker\downloads\completed\books`
+- Applied in `qbittorrent.service.ts` via `PathMapper.reverseTransform()`
+- Ensures qBittorrent knows where to save files
+
+**2. Incoming (qBittorrent → RMAB):** When processing completed downloads
+- qBit reports: `F:\Docker\downloads\completed\books\Audiobook.Name`
+- Translated to RMAB's path: `/downloads/Audiobook.Name`
+- Applied in `monitor-download.processor.ts` via `PathMapper.transform()`
+- Applied in `retry-failed-imports.processor.ts` for failed imports
+- Ensures RMAB can find and organize files
+
 **Implementation:**
 - `PathMapper` utility (`src/lib/utils/path-mapper.ts`) handles transformation
-- Applied in `monitor-download.processor.ts` when download completes
-- Applied in `retry-failed-imports.processor.ts` for failed imports
+- `transform()`: Remote → Local (qBit → RMAB)
+- `reverseTransform()`: Local → Remote (RMAB → qBit)
 - Uses simple prefix replacement with path normalization
-- Graceful fallback: if path doesn't match remote prefix, returns unchanged
+- Preserves Windows backslashes when translating to Windows paths
+- Graceful fallback: if path doesn't match prefix, returns unchanged
+
+**Path Transformation Examples:**
 
-**Path Transformation:**
 ```typescript
-// Input from qBittorrent
-qbPath = "/remote/mnt/d/done/Audiobook.Name"
-
-// Config
-remotePath = "/remote/mnt/d/done"
+// Outgoing: RMAB → qBittorrent (when adding torrent)
 localPath = "/downloads"
+config = { remotePath: "F:\\Docker\\downloads\\completed\\books", localPath: "/downloads" }
+remotePath = PathMapper.reverseTransform(localPath, config)
+// Result: "F:\Docker\downloads\completed\books"
 
-// Output (used for file organization)
-organizePath = "/downloads/Audiobook.Name"
+// Incoming: qBittorrent → RMAB (when processing completion)
+qbPath = "F:\\Docker\\downloads\\completed\\books\\Audiobook.Name"
+config = { remotePath: "F:\\Docker\\downloads\\completed\\books", localPath: "/downloads" }
+organizePath = PathMapper.transform(qbPath, config)
+// Result: "/downloads/Audiobook.Name"
 ```
 
 **Validation:**
@@ -126,9 +145,10 @@ organizePath = "/downloads/Audiobook.Name"
 
 **Behavior:**
 - Mapping only applies when enabled
-- If path doesn't start with remote prefix, returns original (logs warning)
+- If path doesn't start with expected prefix, returns original (logs warning)
 - Path normalization handles trailing slashes, backslashes, redundant separators
 - Works with both `content_path` and constructed `save_path + name`
+- Preserves native path separators (important for Windows)
 
 ## Data Models
 
@@ -188,6 +208,13 @@ type TorrentState = 'downloading' | 'uploading' | 'stalledDL' |
    - Applied to axios client instance and all standalone requests
    - Works transparently with or without reverse proxy
    - Compatible with popular seedbox providers (seedit4.me, etc.)
+**14. Remote path mapping not applied when adding torrents** - When qBittorrent runs locally (e.g., Windows) and RMAB runs in Docker, savepath sent to qBittorrent was not translated. qBittorrent received `/downloads` (RMAB's path) but expected `F:\Docker\downloads\completed\books` (Windows path), causing "Invalid path" errors. Fixed by:
+   - Added `PathMapper.reverseTransform()` for bidirectional path mapping (local → remote)
+   - Applied in `qbittorrent.service.ts` when setting savepath for torrents
+   - Preserves Windows backslashes when translating to Windows paths
+   - Path mapping now works in both directions: outgoing (RMAB → qBit) and incoming (qBit → RMAB)
+   - Service constructor accepts `PathMappingConfig` parameter
+   - Singleton loads path mapping config from database
 
 ## Tech Stack