complete codex docs

docs/modules/fast_download.md

@@ -0,0 +1,53 @@
+# Fast Download
+
+## Purpose
+
+FastDL support for Source/GoldSrc style content distribution.
+
+## Current Status
+
+- Functional
+
+## Dependencies
+
+- web server / FastDL setup
+- access rules
+
+## Database Tables
+
+- `fastdl_access_rules`
+- `fastdl_settings`
+
+## Agent Interaction
+
+- fastdl service management through agent RPC
+
+## User Workflow
+
+- download client assets faster from the server host
+
+## Admin Workflow
+
+- configure rules and server settings
+
+## Security Concerns
+
+- file exposure rules
+- bandwidth / access control
+
+## Known Issues
+
+- niche feature set
+
+## Missing Functionality
+
+- better UI and docs
+
+## Suggested Future Improvements
+
+- keep for Source-family communities
+
+## Recommendation
+
+- Keep
+