docs: condense implementation comments

PROGRESS.md

@@ -10,6 +10,16 @@ up instantly. Newest status at the top.
 
 ## ▶ Where we left off / next action
 
+- **Done (2026-07-23):** **First comment-density cleanup across core, server, and native
+  clients.** Condensed comments in the highest-noise audio, reconnect, registry, and binding
+  files; removed implementation history and narration; retained ABI ownership, threading,
+  real-time, ordering, and OS-API invariants. Moved the durable iOS audio-routing/pacing rules
+  to `docs/voice.md` and client reconnection policy to `docs/protocol.md`. No behavior, wire
+  format, or C ABI changes. **Verification:** `cmake --build --preset dev` green;
+  `ctest --preset dev` 29/29 green. `dotnet build VoiceCat.slnx` restores dependencies and
+  builds `VoiceCat.Interop` + `VoiceCat.App`, then fails in the unchanged test project because
+  `ExternalPcmTests.cs:49` references internal `NativeMethods` (`CS0122`).
+
 - **Done (2026-06-25):** **Fixed iOS AirPods-disconnect reinitialize loop on A2DP presets
   (Stereo Mic / Mono Mic).** Regression from the 2026-06-25 audio-device-change recovery
   commit below, which broadened the route-change recovery set from