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/protocol/src/binary-frames/file-transfer.ts

@@ -14,6 +14,7 @@ export const FileBeginMetadataSchema = z.object({
   size: z.number().int().nonnegative(),
   encoding: z.enum(["utf-8", "binary"]),
   modifiedAt: z.string(),
+  revision: z.string().optional(),
   fileName: z.string().optional(),
 });