feat: add perform_nfo_repair_scan startup hook

docs/CHANGELOG.md

@@ -55,6 +55,13 @@ This changelog follows [Keep a Changelog](https://keepachangelog.com/) principle
   that detects incomplete `tvshow.nfo` files and triggers TMDB re-fetch.
   Provides `parse_nfo_tags()`, `find_missing_tags()`, `nfo_needs_repair()`, and
   `NfoRepairService.repair_series()`.  13 required tags are checked.
+- **`perform_nfo_repair_scan()` startup hook
+  (`src/server/services/initialization_service.py`)**: New async function
+  called during application startup. Iterates every series directory, checks
+  whether `tvshow.nfo` is missing required tags using `nfo_needs_repair()`, and
+  either queues the series for background reload (when a `background_loader` is
+  provided) or calls `NfoRepairService.repair_series()` directly. Skips
+  gracefully when `tmdb_api_key` or `anime_directory` is not configured.
 
 ### Changed