fix: the four reliability findings Sonar reports on dev

- The warmed fonts' key sorts by code units, so the same faces give the same
  key in every locale.
- The nearest weight of a snapshot face starts from the first face it has.
- The round hike search names its candidates with their place in the list
  explicitly instead of handing map a function of two arguments.

client/src/components/Studio/bookFontWarm.ts

@@ -53,9 +53,12 @@ export async function warmBookFaces(
  * Warms the faces of the book the Studio holds whenever the set of faces it
  * uses changes; typing into a text does not, so an edit costs nothing here.
  */
+/** A key compares by code units: the same faces give the same key whatever the locale. */
+const byCodeUnits = (a: string, b: string) => (a < b ? -1 : a > b ? 1 : 0);
+
 export function useWarmBookFaces(): void {
   const doc = useStudioStore((s) => s.doc);
-  const key = useMemo(() => (doc ? bookFacesUsed(doc).map(faceSpec).sort().join('|') : ''), [doc]);
+  const key = useMemo(() => (doc ? bookFacesUsed(doc).map(faceSpec).sort(byCodeUnits).join('|') : ''), [doc]);
   useEffect(() => {
     const current = useStudioStore.getState().doc;
     // A face that will not load is drawn in its fallback, which the picker already shows; nothing to tell anyone.

client/src/components/Studio/snapshotFonts.ts

@@ -120,8 +120,9 @@ export function pickFaceRules(rules: readonly FaceRule[], uses: FaceUses): FaceR
     const slanted = ofFamily.filter((r) => r.italic === (italicText === 'true'));
     const styled = slanted.length ? slanted : ofFamily.filter((r) => !r.italic);
     if (!styled.length) continue;
-    const nearest = styled.reduce((best, r) =>
-      Math.abs(r.weight - weight) < Math.abs(best.weight - weight) ? r : best
+    const nearest = styled.reduce(
+      (best, r) => (Math.abs(r.weight - weight) < Math.abs(best.weight - weight) ? r : best),
+      styled[0]
     ).weight;
     for (const rule of styled) {
       if (rule.weight === nearest && coversAny(rule.unicodeRange, chars)) picked.set(rule.url, rule);

client/src/components/Tours/planner/roundHikeRouting.ts

@@ -64,14 +64,15 @@ export async function findRoundHikes(
 ): Promise<void> {
   const state = await searchRoundLoops(request.start, request.targetM, (spots) => askLoop(request, spots, signal), {
     signal,
-    onStep: ({ found, asked }) => report({ phase: 'searching', candidates: found.map(candidateOf), asked }),
+    onStep: ({ found, asked }) =>
+      report({ phase: 'searching', candidates: found.map((loop, i) => candidateOf(loop, i)), asked }),
   });
   if (signal.aborted) return;
   if (state.answered === 0) {
     report({ phase: 'failed', candidates: [], asked: state.asked });
     return;
   }
-  const found = state.found.map(candidateOf);
+  const found = state.found.map((loop, i) => candidateOf(loop, i));
   let candidates = [...found];
   report({ phase: 'done', candidates, asked: state.asked });
   for (const round of found) {