fix(ui): Match PyCharm project view, matched tags and text weight

- Project widget initials follow IDEA's AvatarUtils.initials ("idea" → "I").
- "Show directories with changed descendants" is off by default, as in IDEA.
- FileEntry gains `excluded`: only excluded folders get the excluded icon and
  dimming; git-ignored ones keep the plain icon and the ignored colour.
- `.github` folders get IDEA's GitHub folder icon.
- Matched tag names are never bold and use their own background
  (MATCHED_TAG_NAME); matched braces are bold in dark schemes only.
- Revert Greyscale antialiasing to `antialiased` for UI and editor; `auto`
  rendered text heavier than PyCharm.

Claude-Session: https://claude.ai/code/session_01SaPPsVPuk6ZTNsoUCNCbMv

src/editor/core/cm/setup.ts

@@ -2,8 +2,9 @@
  * The base extension set of every text editor, with compartments for the
  * parts that change at runtime (language, settings, contributions).
  */
-import { Compartment, EditorState, Prec, type Extension } from "@codemirror/state";
+import { Compartment, EditorState, Prec, type Extension, type Range } from "@codemirror/state";
 import {
+  Decoration,
   EditorView,
   dropCursor,
   highlightActiveLineGutter,
@@ -11,7 +12,14 @@ import {
   keymap,
   lineNumbers,
 } from "@codemirror/view";
-import { bracketMatching, indentOnInput, indentUnit, syntaxHighlighting, type LanguageSupport } from "@codemirror/language";
+import {
+  bracketMatching,
+  indentOnInput,
+  indentUnit,
+  syntaxHighlighting,
+  type LanguageSupport,
+  type MatchResult,
+} from "@codemirror/language";
 import { defaultKeymap, history, historyKeymap, indentWithTab } from "@codemirror/commands";
 import { closeBrackets, closeBracketsKeymap } from "@codemirror/autocomplete";
 import { highlightSelectionMatches } from "@codemirror/search";
@@ -172,11 +180,24 @@ export function stickyExtension(settings: EditorSettings | undefined): Extension
   return settings?.stickyScroll === false || isDistractionFree() ? [] : [stickyScroll, stickyMaxLines.of(prefsOf(settings).codeEditing.stickyLinesMax)];
 }
 
+const matchingBracket = Decoration.mark({ class: "cm-matchingBracket" });
+const matchingTag = Decoration.mark({ class: "cm-matchingBracket cm-matchingTag" });
+const nonmatchingBracket = Decoration.mark({ class: "cm-nonmatchingBracket" });
+
+/** Like the default, but matched tag names (HTML / XML / JSX) get their own mark, as IDEA's MATCHED_TAG_NAME. */
+function renderMatch(match: MatchResult, state: EditorState): readonly Range<Decoration>[] {
+  const mark = (from: number, to: number) =>
+    !match.matched ? nonmatchingBracket : /^[()[\]{}]$/.test(state.sliceDoc(from, to)) ? matchingBracket : matchingTag;
+  const out = [mark(match.start.from, match.start.to).range(match.start.from, match.start.to)];
+  if (match.end) out.push(mark(match.end.from, match.end.to).range(match.end.from, match.end.to));
+  return out;
+}
+
 export function heavyExtension(docLength: number, settings?: EditorSettings): Extension {
   if (docLength > HEAVY_LIMIT) return [];
   const prefs = prefsOf(settings);
   return [
-    prefs.codeEditing.highlightBraces ? bracketMatching() : [],
+    prefs.codeEditing.highlightBraces ? bracketMatching({ renderMatch }) : [],
     prefs.appearance.indentGuides ? indentGuides : [],
     prefs.codeEditing.highlightSelection ? highlightSelectionMatches({ minSelectionLength: 2, maxMatches: 500 }) : [],
   ];

src/editor/core/cm/theme.ts

@@ -67,12 +67,17 @@ export const openideaTheme = EditorView.theme({
   },
   ".cm-activeLine": { backgroundColor: "var(--editor-caret-row)" },
   ".cm-selectionMatch": { backgroundColor: "var(--bg-identifier-under-caret, color-mix(in srgb, var(--fg) 9%, transparent))" },
+  // IDEA's MATCHED_BRACE_ATTRIBUTES (bold in dark schemes only) and MATCHED_TAG_NAME (never bold).
   ".cm-matchingBracket, &.cm-focused .cm-matchingBracket": {
     backgroundColor: "var(--editor-brace)",
     color: "inherit",
-    fontWeight: "700",
+    fontWeight: "var(--matched-brace-weight, 700)",
     borderRadius: "1px",
   },
+  ".cm-matchingTag, &.cm-focused .cm-matchingTag": {
+    backgroundColor: "var(--bg-matched-tag, var(--editor-brace))",
+    fontWeight: "inherit",
+  },
   ".cm-nonmatchingBracket, &.cm-focused .cm-nonmatchingBracket": {
     color: "var(--danger)",
     backgroundColor: "color-mix(in srgb, var(--danger) 14%, transparent)",

src/editor/core/view/navBar.test.ts

@@ -17,7 +17,7 @@ describe("navigation bar popup model", () => {
   });
 
   it("lists folder children without IDE-hidden names, and symbol children", () => {
-    const e = (name: string, kind: FileEntry["kind"]) => ({ name, path: `/p/${name}`, kind, size: 0, mtimeMs: 0, ignored: false, hidden: false }) as FileEntry;
+    const e = (name: string, kind: FileEntry["kind"]) => ({ name, path: `/p/${name}`, kind, size: 0, mtimeMs: 0, ignored: false, excluded: false, hidden: false }) as FileEntry;
     expect(dirChildren([e(".git", "dir"), e("src", "dir"), e("a.ts", "file")]).map((c) => `${c.kind}:${c.label}`)).toEqual(["dir:src", "file:a.ts"]);
     expect(symbolChildren("/p/a.ts", [sym("A", [sym("b")])]).map((c) => c.label)).toEqual(["A"]);
   });