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/tooth-intent.resolver.ts

@@ -18,18 +18,14 @@ export type ToothResolution = {
 
 /** Everything here parses untrusted model output, so nothing may throw. */
 function normalizedFdi(intent: ToothIntent): string {
-  // Same normalisation the wire layer used to pick this branch, so the two cannot
-  // disagree: '14 ' is tooth 14 through the treatment API and '۲۶' is tooth 26, and
-  // neither may be reported as malformed here.
+  // The same normalisation the wire layer used to pick this branch, so the two agree.
   return normalizeFdiCode((intent as { fdi?: unknown }).fdi);
 }
 
 /**
- * Resolve one spoken tooth reference to an FDI code, or null.
- *
- * Never guesses and never clamps: a position of 9, a deciduous tooth, or a malformed
- * intent resolves to null so the caller can surface it as "not understood" rather than
- * silently selecting a neighbouring tooth.
+ * Never guesses and never clamps: position 9, a deciduous tooth or a malformed intent all
+ * resolve to null, so the caller surfaces "not understood" rather than silently selecting a
+ * neighbouring tooth.
  */
 export function resolveToothIntent(intent: ToothIntent): string | null {
   if (!intent || typeof intent !== 'object') return null;
@@ -65,9 +61,8 @@ function unresolvedReason(intent: ToothIntent): UnresolvedItem['reason'] {
       intent.position < 1 ||
       intent.position > 8;
     if (positionBad) return 'position_out_of_range';
-    // The position was understood, so the words were not the problem: the speaker never
-    // said which quadrant. "دندون دو" names four teeth at once, and telling the
-    // clinician it "could not be read" would send them looking for the wrong fault.
+    // The position was understood; the quadrant was never said. "دندون دو" names four
+    // teeth, so "could not be read" would send the clinician after the wrong fault.
     const archMissing = intent.arch !== 'upper' && intent.arch !== 'lower';
     const sideMissing =
       intent.side !== 'patient_right' && intent.side !== 'patient_left';
@@ -78,11 +73,8 @@ function unresolvedReason(intent: ToothIntent): UnresolvedItem['reason'] {
 }
 
 /**
- * The teeth still consistent with what *was* heard.
- *
- * Narrowed by whatever the clinician did say, so "دو" offers four and "دو بالا" offers
- * two. This is not a guess — it is the full set of readings, handed to the clinician to
- * choose from rather than picked on their behalf.
+ * The teeth still consistent with what *was* heard — "دو" leaves four, "دو بالا" two. Not
+ * a guess: the full set of readings, for the clinician to choose from.
  */
 function quadrantCandidates(intent: ToothIntent): string[] {
   if (intent.kind !== 'positional') return [];
@@ -109,11 +101,8 @@ function spokenOf(intent: ToothIntent): string {
 }
 
 /**
- * Resolve a list of spoken tooth references.
- *
- * Duplicates collapse — a clinician may name the same tooth twice in one sentence — and
- * anything unresolvable is reported rather than dropped, so the review sheet can show the
- * user exactly which words were not understood.
+ * Duplicates collapse; anything unresolvable is reported rather than dropped, so the sheet
+ * can show which words were not understood.
  */
 export function resolveToothIntents(
   intents: readonly ToothIntent[],
@@ -138,10 +127,8 @@ export function resolveToothIntents(
     const spoken = spokenOf(intent);
     const candidates =
       reason === 'tooth_missing_quadrant' ? quadrantCandidates(intent) : [];
-    // Only dedupe items we can actually tell apart. Without `spoken`, two distinct lost
-    // references would collapse into one blank review row and a tooth would vanish. The
-    // candidates are part of the identity: the same word with a different arch heard
-    // offers a different choice.
+    // Only dedupe what we can tell apart: without `spoken`, two lost references collapse
+    // into one blank row and a tooth vanishes. Candidates are part of the identity.
     if (spoken) {
       const key = `${spoken}::${reason}::${candidates.join(',')}`;
       if (seenUnresolved.has(key)) continue;