feat(frontend): let the clinician pick the tooth from the candidates

An under-specified tooth was a dead end: the sheet said what was missing
and the clinician had to leave and hunt for it on the chart. The readings
are enumerable, so the review sheet now renders them as chips — the one
interactive part of an otherwise read-only confirmation step.

A pick is folded into the result by withChosenTeeth() rather than tracked
alongside it, so the rows, the mini chart, the prosthesis warning and
applyVoiceResult all keep reading a single VoiceExtractionResult and none
of them has to know the chips exist. It unions rather than toggles: a
candidate can coincidentally be a tooth the recording already produced, and
tapping it must not deselect that one.

Two things that would otherwise make the chips look functional while
applying nothing: the teeth row is ticked on the first pick (it starts
unticked when the recording produced no teeth of its own), and the apply
count is now intersected with row availability so it cannot promise to
apply a row with nothing in it.

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

frontend/src/components/treatment/voiceReviewRows.ts

@@ -1,5 +1,10 @@
+import { groupsFromFlatTeeth } from '@/components/treatment/toothSelectionGroups';
 import type { FdiToothId } from '@/types/treatment';
-import type { VoiceApplySelection, VoiceExtractionResult } from '@/types/voice';
+import type {
+  VoiceApplySelection,
+  VoiceExtractionResult,
+  VoiceProsthesisResult,
+} from '@/types/voice';
 
 /** Which rows the review sheet renders at all — a row with nothing extracted is noise. */
 export function voiceRowAvailability(result: VoiceExtractionResult) {
@@ -35,9 +40,57 @@ export function initialVoiceSelection(result: VoiceExtractionResult): VoiceApply
   };
 }
 
-/** How many rows will actually be applied — drives the confirm button's label. */
-export function countSelected(selection: VoiceApplySelection): number {
-  return Object.values(selection).filter(Boolean).length;
+/**
+ * How many rows will actually be applied — drives the confirm button's label.
+ *
+ * Intersected with availability rather than counting ticks: a row can be ticked and then
+ * lose its content (the last candidate tooth un-picked), and "Apply 1 item" that applies
+ * nothing is worse than a wrong number.
+ */
+export function countSelected(
+  selection: VoiceApplySelection,
+  available: Record<keyof VoiceApplySelection, boolean>,
+): number {
+  return (Object.keys(selection) as (keyof VoiceApplySelection)[]).filter(
+    (key) => selection[key] && available[key],
+  ).length;
+}
+
+/** Mirrors the backend's rule: every selected tooth needs a code, or the case cannot ship. */
+function recheckProsthesis(
+  prosthesis: VoiceProsthesisResult,
+  teeth: readonly FdiToothId[],
+): VoiceProsthesisResult {
+  const missingTeeth = teeth.filter((tooth) => !prosthesis.byTooth[tooth]);
+  return { ...prosthesis, missingTeeth, complete: missingTeeth.length === 0 };
+}
+
+/**
+ * Fold the clinician's candidate picks into the extracted result.
+ *
+ * Everything downstream reads a `VoiceExtractionResult` — row availability, the mini
+ * chart, the prosthesis warning, `applyVoiceResult` — so resolving the picks into one here
+ * means none of them has to know the chips exist.
+ *
+ * Union rather than toggle, for two reasons: a candidate can coincidentally be a tooth the
+ * recording already produced ("۱۲ و دو"), where tapping it must not deselect that tooth;
+ * and `groupsFromFlatTeeth` keeps the bridges intact while giving every remaining tooth a
+ * single group, so no tooth can be lost on the way through.
+ */
+export function withChosenTeeth(
+  result: VoiceExtractionResult,
+  chosen: readonly FdiToothId[],
+): VoiceExtractionResult {
+  if (chosen.length === 0) return result;
+
+  const teeth = [...new Set([...result.teeth, ...chosen])].sort() as FdiToothId[];
+
+  return {
+    ...result,
+    teeth,
+    toothSelectionGroups: groupsFromFlatTeeth(teeth, result.toothSelectionGroups),
+    prosthesis: result.prosthesis ? recheckProsthesis(result.prosthesis, teeth) : null,
+  };
 }
 
 /** Teeth that are part of a bridge, for the read-only chart's connection marks. */