Docs: Update all documentation for series loading and episode tracking fixes

docs/CHANGELOG.md

@@ -35,6 +35,30 @@ This document tracks all notable changes to the Aniworld project.
 
 This changelog follows [Keep a Changelog](https://keepachangelog.com/) principles and adheres to [Semantic Versioning](https://semver.org/).
 
+---
+
+## [Unreleased] - 2026-01-18
+
+### Fixed
+
+- **Series Visibility**: Fixed issue where series added to the database weren't appearing in the API/UI
+  - Series are now loaded from database into SeriesApp's in-memory cache on startup
+  - Added `_load_series_from_db()` call after initial database sync in FastAPI lifespan
+- **Episode Tracking**: Fixed missing episodes not being saved to database when adding new series
+  - Missing episodes are now persisted to the `episodes` table after the targeted scan
+  - Episodes are properly synced during rescan operations (added/removed based on filesystem state)
+- **Database Synchronization**: Improved data consistency between database and in-memory cache
+  - Rescan process properly updates episodes: adds new missing episodes, removes downloaded ones
+  - All series operations now maintain database and cache synchronization
+
+### Technical Details
+
+- Modified `src/server/fastapi_app.py` to load series from database after sync
+- Modified `src/server/api/anime.py` to save scanned episodes to database
+- Episodes table properly tracks missing episodes with automatic cleanup
+
+---
+
 ## Sections for Each Release
 
 ```markdown