docs: cut the comments that were not earning their place

I wrote 731 comment lines on this branch against 4,530 lines of code — 14%,
where the rest of the repo runs at 1.8%. CLAUDE.md asks for code that reads
like its surroundings, and this did not.

Removed by genre rather than by taste:

- restating the code, e.g. "JS getUTCDay() numbering: Sunday = 0" above the
  map that literally shows it, and a docblock on startOfWeek explaining that
  it returns the start of the week;
- narrating history — "this used to rebuild the whole map", "left the bar
  recording forever" — which the commit message and git blame already carry;
- saying the same thing in several places: the "cannot record is not a
  denied microphone" reason appeared three times in one file, and the
  "aborting stops a per-minute metered call" reason across three files. Each
  now lives once, where the behaviour it explains lives;
- defending decisions nobody would question, like why toLatinDigits is its
  own module;
- over-explaining defensive branches, three separate comments to distinguish
  null from missing-kind from unrecognised-kind.

What stays is what the code cannot say: the patient-right convention in
toFdi, whose failure mode is a valid code for the wrong tooth; the
"this"-vs-"next" week anchoring; StrictMode re-arming mountedRef; Safari
accepting no mimeType hint; and the invariants whose violation already cost
a bug — the body parser's middleware ordering and the dispatch panel's
auto-fill rules.

Comments only. The diff contains no non-comment line.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

backend/src/modules/voice/voice.service.ts

@@ -55,10 +55,8 @@ export class VoiceService {
   }
 
   /**
-   * What the frontend needs to decide whether to render the microphone at all.
-   *
-   * v1 ships ungated beyond a configured locale profile — no plan check. The
-   * Plan.features design is deferred, not dropped.
+   * What the frontend needs to decide whether to render the microphone. v1 is ungated beyond
+   * a configured locale profile; the Plan.features design is deferred, not dropped.
    */
   getAvailability(): VoiceAvailability {
     const voice = this.voiceConfig;
@@ -107,10 +105,9 @@ export class VoiceService {
       throw this.toAppException(error, 'asr');
     }
 
-    // durationMs is client-reported and therefore not enforcement. usage.seconds is the
-    // vendor's own measurement of the audio it decoded, so a client under-reporting length
-    // to slip past the cap is caught here — after the ASR spend, but before the extraction
-    // call, and visibly in telemetry.
+    // durationMs is client-reported, so not enforcement. usage.seconds is the vendor's own
+    // measurement — a client under-reporting to slip past the cap is caught here, after the
+    // ASR spend but before the more expensive extraction call.
     if (asrSeconds != null) {
       this.assertWithinCap(asrSeconds * 1000);
     }
@@ -211,13 +208,9 @@ export class VoiceService {
   }
 
   /**
-   * Grace above the configured cap.
-   *
-   * The client auto-stops when elapsed >= maxMs, then measures the final length after the
-   * recorder has actually stopped — so a recording that runs to the cap always reports
-   * slightly over it. Without this tolerance the auto-stop would guarantee a rejection,
-   * discarding exactly the recording it was meant to save. The client still reports the
-   * true length, so telemetry stays honest.
+   * The client auto-stops at maxMs and only then measures, so a capped recording always
+   * reports slightly over. Without this tolerance every auto-stopped recording — the exact
+   * case the cap exists for — would be rejected as too long.
    */
   private static readonly CAP_TOLERANCE_MS = 2_000;
 
@@ -319,10 +312,7 @@ export class VoiceService {
     );
   }
 
-  /**
-   * Structured, patient-free. Never the transcript, never audio, never a patient id.
-   * Log lines are the interim sink until this repo has metrics infrastructure.
-   */
+  /** Structured and patient-free: never the transcript, never audio, never a patient id. */
   private logTelemetry(input: {
     locale: string;
     durationMs: number;