Clean up pass

docs/NEW_RENDER_CADENCE_APP_PLAN.md

@@ -104,6 +104,13 @@ apps/RenderCadenceCompositor/
     RenderCadenceApp.h
     AppConfig.cpp
     AppConfig.h
+    AppConfigProvider.cpp
+    AppConfigProvider.h
+
+  control/
+    HttpControlServer.cpp
+    HttpControlServer.h
+    RuntimeStateJson.h
 
   platform/
     ComInit.cpp
@@ -139,8 +146,16 @@ apps/RenderCadenceCompositor/
   telemetry/
     CadenceTelemetry.cpp
     CadenceTelemetry.h
-    TelemetryPrinter.cpp
-    TelemetryPrinter.h
+    CadenceTelemetryJson.h
+    TelemetryHealthMonitor.h
+
+  logging/
+    Logger.cpp
+    Logger.h
+
+  json/
+    JsonWriter.cpp
+    JsonWriter.h
 ```
 
 The new app can reuse selected existing source files from the current app at first:
@@ -355,15 +370,17 @@ Initial counters:
 - free/rendering/completed/scheduled slot counts
 - actual DeckLink buffered frames
 
-### `TelemetryPrinter`
+### `TelemetryHealthMonitor`
 
-Prints one stable line per interval, matching the probe where possible.
+Samples cadence telemetry once per interval and logs only health events.
 
-Example:
+Normal telemetry is available through the HTTP state endpoint. The console should not receive a healthy once-per-second cadence line.
 
-```text
-renderFps=59.9 scheduleFps=59.9 free=7 completed=1 scheduled=4 drops=0 pboMiss=0 completions=119 late=0 dropped=0 decklinkBuffered=4
-```
+Health events:
+
+- warning when DeckLink late/dropped-frame counters increase
+- warning when schedule failures increase
+- error when app/DeckLink output buffering is starved
 
 ## Startup Sequence
 
@@ -371,24 +388,28 @@ Target first-version startup:
 
 ```text
 main
-  -> parse AppConfig
+  -> load AppConfig through AppConfigProvider
   -> initialize COM
-  -> DeckLinkOutput discover/select/configure output
-  -> DeckLinkOutput prepare output schedule
   -> create SystemFrameExchange
   -> start RenderThread
   -> wait for completed frame warmup
-  -> start DeckLinkOutputThread
-  -> wait for scheduled depth warmup
-  -> DeckLinkOutput start scheduled playback
-  -> start TelemetryPrinter
+  -> optionally discover/select/configure DeckLink output
+  -> if DeckLink is available:
+       -> start DeckLinkOutputThread
+       -> wait for scheduled depth warmup
+       -> DeckLinkOutput start scheduled playback
+  -> if DeckLink is unavailable:
+       -> continue without video output
+  -> start TelemetryHealthMonitor
+  -> start HttpControlServer
   -> wait for Enter
 ```
 
 Shutdown:
 
 ```text
-stop TelemetryPrinter
+stop HttpControlServer
+stop TelemetryHealthMonitor
 stop DeckLinkOutputThread
 DeckLinkOutput stop playback
 stop RenderThread