Edit workspace files directly on web (#2270)

* feat(files): edit workspace files on web

Keep source buffers synchronized with host file changes and require an explicit overwrite or reload when revisions diverge.

* feat(panels): surface and protect modified tabs

Expose tooltip and modification state through the generic panel boundary so tabs can show stable metadata and guard every close route consistently.

* fix(tests): use portable fake timeout handle

* fix(files): harden editor conflict handling

Preserve modified panel state across tab eviction, use precise revisions for optimistic writes, coalesce concurrent file watchers, and localize the editor interface.

* fix(files): close editor concurrency gaps

Coalesce clean reloads, preserve subscriber identities and file permissions, suspend pending saves during close confirmation, and carry precise revisions through file reads.

* test(files): expect read revision metadata

packages/highlight/package.json

@@ -27,7 +27,7 @@
     "typecheck": "tsgo --noEmit"
   },
   "dependencies": {
-    "@codemirror/language": "^6.12.3",
+    "@codemirror/language": "6.12.4",
     "@codemirror/legacy-modes": "^6.5.3",
     "@lezer/common": "^1.5.0",
     "@lezer/cpp": "^1.1.5",