Add verbose mode, progress indicators, and missing media log

- Add --verbose flag to sync commands for detailed API request/response output
- Add progress indicators (.=#xPpE|) for compact sync output
- Implement exponential backoff (1s, 2s, 4s, 8s, 16s) for media downloads
- Log failed media downloads to wp-content/uploads/mls-missing-media.log
- Add 'wp mls cache missing' command to view/clear the log
- Retry on rate limit (429) and server errors (5xx)
- Update documentation with new features

Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

wp-content/plugins/mls-by-hansonxyz/docs/CLAUDE.md

@@ -61,10 +61,10 @@ wp mls test auth
 wp mls status
 wp mls status rate-limits
 
-# Run sync
-wp mls sync full [--dry-run] [--limit=N]
-wp mls sync incremental [--dry-run]
-wp mls sync media [--limit=N]
+# Run sync (use --verbose for detailed output)
+wp mls sync full [--dry-run] [--limit=N] [--verbose]
+wp mls sync incremental [--dry-run] [--verbose]
+wp mls sync media [--limit=N] [--verbose]
 wp mls sync resume --id=<sync_id>
 
 # Statistics
@@ -73,8 +73,33 @@ wp mls stats
 # Cache management
 wp mls cache clear --confirm
 wp mls cache cleanup
+wp mls cache missing              # View failed media downloads
+wp mls cache missing --limit=20   # View first 20 entries
+wp mls cache missing --clear      # Clear the log
 ```
 
+### Progress Output
+
+Without --verbose (compact mode):
+- `.` = new property created
+- `#` = property updated
+- `x` = property deleted
+- `-` = skipped (dry-run)
+- `P` = photo downloaded
+- `p` = photo skipped (already exists)
+- `E` = photo error
+- `|` = page complete
+
+With --verbose: Full timestamped output showing API requests, responses, and individual item status.
+
+### Missing Media Log
+
+Failed media downloads are logged to: `wp-content/uploads/mls-missing-media.log`
+
+Format: `[timestamp] listing_key | media_key | error | url`
+
+Media downloads use exponential backoff (1s, 2s, 4s, 8s, 16s) for rate limit (429) and server errors (5xx).
+
 ### Public API Functions
 
 Available for themes/plugins: