Share one fuzzy matcher across both dialogs

Plugins dialog and the Speed Dial popup each
carried a private copy of the same fuzzy
matcher and had already drifted. Move the
pure functions into a shared module loaded
by both pages, and add a unit test beside
it.

resources/web/js/fuzzy-search.js

@@ -0,0 +1,58 @@
+// Shared fuzzy-search core for the webview dialogs (Plugins dialog, Speed Dial popup).
+// why: both pages carried their own copy of this matcher and had already drifted; one source of truth.
+// note: keep this DOM-free and plain global-scope (no export/module) - it is loaded by <script src> in
+//       each page AND by a node vm.runInContext in the speed-dial logic test. It MUST be loaded before
+//       the page script that calls it.
+
+// Fold per-character so matched offsets stay in ORIGINAL string coordinates (highlighting slices the
+// original text; a separately-folded string would desync offsets).
+function FoldChar(ch) {
+  return ch.normalize("NFD").replace(/\p{Diacritic}/gu, ""); // accents always folded
+}
+
+function Norm(ch, caseSensitive) {
+  const folded = FoldChar(ch);
+  return caseSensitive ? folded : folded.toLowerCase(); // case-sensitivity is the only toggle
+}
+
+function EscapeRegExp(value) {
+  return value.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
+}
+
+// Fuzzy: ordered subsequence. Builds ranges in original coordinates, merging adjacent runs on the fly.
+function FuzzyRanges(text, query, caseSensitive) {
+  const t = text || "";
+  const needle = Array.from(query || "").map((ch) => Norm(ch, caseSensitive)).join("");
+  if (!needle)
+    return null;
+  const ranges = [];
+  let qi = 0;
+  for (let i = 0; i < t.length && qi < needle.length; i++) {
+    if (Norm(t[i], caseSensitive) === needle[qi]) {
+      const last = ranges[ranges.length - 1];
+      if (last && last[1] === i)
+        last[1] = i + 1;
+      else
+        ranges.push([i, i + 1]);
+      qi++;
+    }
+  }
+  return qi === needle.length ? ranges : null;
+}
+
+// Whole word: literal \b-bounded match that bypasses fuzzy. The per-char fold keeps the haystack
+// length-aligned to the original text, so regex indices map straight back to original offsets.
+// note: one-to-many folds (ligatures, eszett) shift offsets by a char; rare in names, cosmetic only.
+function WholeWordRanges(text, query, caseSensitive) {
+  const haystack = Array.from(text || "").map((ch) => Norm(ch, caseSensitive)).join("");
+  const needle = Array.from(query || "").map((ch) => Norm(ch, caseSensitive)).join("");
+  if (!needle)
+    return null;
+  const re = new RegExp(`\\b${EscapeRegExp(needle)}\\b`, "g");
+  const ranges = [];
+  let match;
+  // why: needle is non-empty, so \b-bounded matches are never zero-length - no empty-match guard needed.
+  while ((match = re.exec(haystack)) !== null)
+    ranges.push([match.index, match.index + match[0].length]);
+  return ranges.length > 0 ? ranges : null;
+}