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/app/src/i18n/resources/en.ts

@@ -465,6 +465,7 @@ export const en = {
     },
     tabs: {
       loading: "Loading...",
+      modified: "Unsaved changes",
       loadingAgentTitle: "Loading agent title",
       emptyPane: "No tabs in this pane.",
       fallback: {
@@ -534,6 +535,12 @@ export const en = {
         close: "Close",
         cancel: "Cancel",
         archive: "Archive",
+        unsavedTitle: "Unsaved changes",
+        unsavedMessage:
+          "This tab has changes that have not been saved. Closing it will discard the draft.",
+        closeWithoutSaving: "Close without saving",
+        closePaneTitle: "Close pane?",
+        bulkUnsaved: "{{count}} tab(s) have unsaved changes. Closing will discard those drafts.",
         closeTerminalTitle: "Close terminal?",
         closeTerminalMessage: "Any running process in this terminal will be stopped immediately.",
         archiveRunningAgentTitle: "Archive running agent?",
@@ -1457,6 +1464,25 @@ export const en = {
       binaryPreviewUnavailable: "Binary preview unavailable",
       failedToLoad: "Failed to load file",
       failedToLoadPreview: "Failed to load file preview",
+      editor: {
+        fileSize: "File size {{size}}",
+        lines: "{{count}} lines",
+        editorStatus: "Editor status {{status}}",
+        unsavedChanges: "Unsaved changes",
+        saving: "Saving...",
+        saveFailed: "Save failed",
+        changedOnDisk: "Changed on disk",
+        vimMode: "Vim mode {{mode}}",
+        cursor: "Line {{line}}, column {{column}}",
+        preview: "Preview",
+        source: "Source",
+        unavailableTitle: "File unavailable on disk",
+        conflictDescription: "The local buffer was preserved. Choose which version to keep.",
+        overwrite: "Overwrite",
+        reload: "Reload",
+        reloadTitle: "Reload from disk?",
+        reloadMessage: "Your local changes will be lost.",
+      },
     },
     diff: {
       changesLabel: "Changes",
@@ -1552,12 +1578,18 @@ export const en = {
     sections: {
       general: "General",
       appearance: "Appearance",
+      editor: "Editor",
       shortcuts: "Shortcuts",
       integrations: "Integrations",
       permissions: "Permissions",
       diagnostics: "Diagnostics",
       about: "About",
     },
+    editor: {
+      title: "Editor",
+      vimKeybindings: "Vim keybindings",
+      vimHint: "Applies to source files on web and desktop.",
+    },
     hostSections: {
       connections: "Connections",
       agents: "Agents",