added optional web component UI control

docs/CURRENT_SYSTEM_ARCHITECTURE.md

@@ -77,6 +77,7 @@ The checked-in implementation is `ShaderRuntimeContentController`. It wraps `Run
 - build state and message
 - bypass state
 - manifest parameter definitions
+- optional shader-declared custom UI metadata
 - current parameter values
 - render-ready artifacts
 
@@ -111,6 +112,7 @@ The host configuration editor is separate from runtime layer persistence. The UI
 - rescan `shaders/`
 - re-read manifests
 - rebuild the supported shader catalog
+- refresh optional shader custom UI metadata
 - update active layer metadata and parameter definitions from changed manifests
 - preserve compatible parameter values
 - default new or incompatible parameter values
@@ -155,6 +157,7 @@ Screenshot routes are present in the UI/OpenAPI surface but are not implemented
 The HTTP server runs on its own thread. `HttpControlServer` owns socket lifetime, HTTP parsing, static asset helpers, OpenAPI/Swagger helper serving, and WebSocket state transport. `RenderCadenceHttpRoutes` owns this app's current endpoint map:
 
 - UI assets
+- shader package custom UI assets under `/shader-assets/{shaderId}/...`
 - OpenAPI/Swagger docs
 - `GET /api/state`
 - `/ws` state updates