feat: wire voice entry into the treatment workspace

Makes the feature reachable end to end: availability is fetched alongside the
catalogs, the capture hook drives the segmented control, and confirming the
review sheet appends a new detail.

Confirm always appends — it never edits an existing detail and never calls
onAddDetail. Ticked rows land on top of the seeded defaults, so unticking the
type row leaves the appointment-purpose default rather than a blank. Lab-side
rows ride on a lab case draft keyed by the detail's *client* id, so a brand-new
unsaved detail can carry a lab, due date and per-tooth prosthesis map.

Availability comes from the API rather than a NEXT_PUBLIC_* var, since those are
baked in at build time; a failure fetching it degrades to no microphone rather
than taking the treatment tab down.

From review of this commit:

- Unticking "teeth" while leaving "prosthesis" ticked attached prosthesis rows
  for teeth the detail does not contain. Nothing downstream filters them —
  assertCompleteToothProsthesisMap only checks detail-teeth ⊆ map, never the
  reverse — so they would have reached task generation as lab work for teeth
  nobody is treating. The map is now filtered to the detail's own teeth.
- The microphone was gated on the URL locale while the server resolved
  everything from req.user.language. Those diverge (a bookmarked /fa/ URL, a
  language toggle whose save failed), which would transcribe Persian with an
  English hint and anchor "next Thursday" to a Monday week instead of a Saturday
  one — or 403 from a visibly-enabled button. The client now sends the locale the
  microphone was offered in, so the gate and the request agree by construction.

Also fixed from the previous review: a civil YYYY-MM-DD date rendered a day
early west of Greenwich (parsed as UTC midnight); the missing-teeth list
hardcoded the Arabic comma for all locales; and voiceApply had no ICU plural, so
the common single-field case read "Apply 1 fields".

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

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

@@ -124,10 +124,12 @@ export class VoiceService {
 
     // Stage 2 — structure it. On failure the transcript still goes back to the client so
     // the words the clinician already paid for are not lost (transcript salvage).
-    const catalog = await this.buildCatalog(organizationId, catalogLocale);
     let resolved: ResolvedExtraction;
     let llmCost: number | null = null;
     try {
+      // Inside the try: the transcript is already paid for, so a catalog/DB failure here
+      // must still salvage it rather than becoming a generic 500 that throws it away.
+      const catalog = await this.buildCatalog(organizationId, catalogLocale);
       const result = await extraction.extract(
         transcript,
         catalog,