feat: edit in the Changes panel, git graph history, plan quota (v2.3.0)

- Changes panel: a working file opens in a CodeMirror editor with its diff
  inline (DiffEditor.tsx, @codemirror/merge, lazy-loaded); Changes folds the
  unchanged lines, Whole file shows them; side by side at 50/50 and full
  width; a Revert per block; original from HEAD or the branch's merge base
  (`mergeBase` on GET /git/changes?range=branch)
- Every diff: green = line added whole, red = removed whole, blue = edited
  in place (--diff-mod)
- History drawn as a commit graph (#58: `parents` on GET /git/log,
  --date-order; lib/commitGraph.ts)
- Per-workspace never-stage list, drawn orange in the Files tree (--kept);
  closed Terminal rows past three deleted
- Status bar plan quota for Claude (per account) and Codex
  (GET /api/pricing/quota, server/lib/quota.js); compact hover panel that
  stays open, Refresh button with a spinner
- Settings → Appearance holds language, theme and pet; Ctrl+Shift+C copies;
  compact sidebar navigation and short session times

client/src/i18n/locales/en/lanes.json

@@ -60,6 +60,9 @@
   "changes.commitPlaceholder": "Commit message",
   "changes.commitStaged": "Commit {{count}} staged",
   "changes.suggestMessage": "Suggest a commit message with AI (Claude, staged changes)",
+  "changes.neverStage": "Never stage — Stage all skips this file",
+  "changes.allowStage": "Include in Stage all again",
+  "changes.keptHint": "Never staged by Stage all (this browser)",
   "changes.conflicted": "conflict",
   "changes.discard": "Discard this file's changes",
   "changes.discardConfirm": "Click again to discard — this cannot be undone",
@@ -113,6 +116,7 @@
   "changes.truncated": "Some changes were left out to keep this panel responsive.",
   "changes.unavailable": "This workspace's directory is not a readable git repository.",
   "changes.unstage": "Unstage this file",
+  "changes.changesView": "Changes",
   "changes.wholeFile": "Whole file",
   "confirmRemoveCancel": "Cancel",
   "confirmRemoveConfirm": "Remove",
@@ -239,8 +243,8 @@
   "changes.undoHunkShortConfirm": "Confirm undo",
   "changes.edit": "Edit",
   "changes.save": "Save",
+  "changes.revertBlock": "Revert",
   "changes.cancelEdit": "Cancel",
-  "changes.clickToEdit": "Click the text to edit",
   "changes.preview": "Preview",
   "changes.raw": "Raw",
   "changes.editorLabel": "Edit {{path}}",