Add ASIN support to file organization and metadata

This update enhances audiobook file organization by including the ASIN in folder names and embedding it as a custom metadata tag in audio files (M4B/M4A/MP3). Documentation is updated to reflect the new folder naming convention and metadata tagging. Additionally, local login and registration can now be disabled via an environment variable, and the interactive torrent search modal allows custom search titles for all modes.

documentation/phase3/file-organization.md

@@ -11,11 +11,21 @@ Target directory read from database config `media_dir` (configurable in setup wi
 ```
 [media_dir]/
 └── Author Name/
-    └── Book Title (Year)/
+    └── Book Title (Year) ASIN/
         ├── Book Title.m4b
         └── cover.jpg
 ```
 
+**Folder naming format:**
+- With year and ASIN: `Book Title (Year) ASIN`
+- With ASIN only: `Book Title ASIN`
+- With year only: `Book Title (Year)`
+- Fallback: `Book Title`
+
+**Example:** `Douglas Adams/The Hitchhiker's Guide to the Galaxy (2005) B0009JKV9W/`
+
+**Rationale:** Including ASIN in folder name improves Plex/Audnexus agent matching accuracy.
+
 Default: `/media/audiobooks/` (if not configured)
 
 ## Process
@@ -23,9 +33,9 @@ Default: `/media/audiobooks/` (if not configured)
 1. Download completes in `/downloads/[torrent-name]/` or `/downloads/[filename]` (single file)
 2. Identify audiobook files (.m4b, .m4a, .mp3) - supports both directories and single files
 3. Read media directory from database config `media_dir`
-4. Create `[media_dir]/[Author]/[Title]/`
+4. Create `[media_dir]/[Author]/[Title (Year) ASIN]/`
 5. **Copy** files (not move - originals stay for seeding)
-6. **Tag metadata** (if enabled) - writes correct title, author, narrator to audio files
+6. **Tag metadata** (if enabled) - writes correct title, author, narrator, ASIN to audio files
 7. Copy cover art if found, else download from Audible
 8. Originals remain until seeding requirements met
 
@@ -46,6 +56,18 @@ Default: `/media/audiobooks/` (if not configured)
 - `artist` - Author (fallback)
 - `composer` - Narrator (standard audiobook field)
 - `date` - Year
+- `ASIN` - Audible ASIN (custom tag)
+  - M4B/M4A/MP4: `----:com.apple.iTunes:ASIN`
+  - MP3: Custom ID3v2 tag
+
+**Note:** ASIN is a custom metadata tag and may not appear in standard file properties viewers (Windows/macOS/Linux). Use specialized tools to verify:
+```bash
+# Verify ASIN metadata with ffprobe
+ffprobe -v quiet -print_format json -show_format "audiobook.m4b" | grep -i asin
+
+# Or use exiftool
+exiftool "audiobook.m4b" | grep -i asin
+```
 
 **Configuration:**
 - Key: `metadata_tagging_enabled` (Configuration table)
@@ -65,6 +87,7 @@ Default: `/media/audiobooks/` (if not configured)
 - Ensures Plex can match audiobooks correctly
 - Writes metadata from Audible/Audnexus (known accurate)
 - Prevents "[Various Albums]" and other metadata issues
+- Embeds ASIN directly in audio files for better identification and matching
 
 **Tech Stack:**
 - ffmpeg (system dependency - included in Docker image)
@@ -103,7 +126,7 @@ interface OrganizationResult {
 
 async function organize(
   downloadPath: string,
-  audiobook: {title: string, author: string, year?: number, coverArtUrl?: string}
+  audiobook: {title: string, author: string, year?: number, coverArtUrl?: string, asin?: string}
 ): Promise<OrganizationResult>;
 ```