complete codex docs

docs/decisions/0004-workshop-system.md

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+# Decision 0004: Server Content Manager Is The Workshop Layer
+
+## Status
+
+Accepted
+
+## Decision
+
+`Panel/modules/addonsmanager` should remain the primary future home for Workshop items, mods, add-ons, and server content. `steam_workshop` should remain a deprecated compatibility layer only.
+
+## Reasoning
+
+- `addonsmanager` already has the richer schema and more complete product direction.
+- It supports content types beyond Steam Workshop.
+- It is a better fit for load order, enable/disable, install history, and metadata.
+
+## Alternatives Considered
+
+- keep `steam_workshop` as the main module
+- split mods, add-ons, and Workshop into separate modules
+
+## Why Those Were Not Chosen
+
+- `steam_workshop` is explicitly deprecated in the codebase.
+- Separate modules would fragment user workflows and duplicate install logic.
+