Refactor code structure for improved readability and maintainability

CHANGELOG.md

@@ -14,6 +14,7 @@
 - Added a dedicated plain TypeScript admin module for tab navigation, media CRUD actions, schedule/system analytics refresh, and moderation workflows without Alpine dependencies.
 - Added resumable chunked admin media upload flow with upload-session endpoints and client progress indicators.
 - Expanded architecture documentation with scaling strategy, API surface reference, detailed video normalization spec, and Cloudflare configuration reference.
+- Added `API.md`, `DEPLOYMENT.md`, `MONITORING.md`, and `SECURITY.md` as dedicated operational documentation guides.
 
 ### Changed
 
@@ -24,6 +25,7 @@
 - Switched the frontend theme to dark-mode-first token defaults with a light-scheme override path for users who prefer light appearance.
 - Refactored the viewer page to a single header plus unified content layout with responsive video/chat split, mobile stacking, and chat panel toggle behavior.
 - Code-split `hls.js` via lazy loading in the viewer bootstrap to shrink the main frontend bundle and isolate stream playback logic into a dedicated chunk.
+- Added navigation links in root README and architecture docs to the new API, deployment, monitoring, and security guide files.
 
 ### Fixed