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/lib/format.ts

@@ -337,23 +337,26 @@ export function formatMs(ms: number): string {
  * Formats how long ago an ISO/SQLite timestamp was, as a translated relative
  * string ("just now", "5m ago", "3h ago", "2d ago") using {@link i18n}.
  * @param iso A past timestamp (see {@link parseDate}).
+ * @param short Drop the "ago" ("now", "5m") — the `common:time.*Short` keys.
  * @returns A localized relative-time phrase; i18next handles pluralization via `count`.
  * @remarks Thresholds cascade seconds -> minutes -> hours -> days (days is the largest
  *   bucket, so a 40-day-old event reads "40d ago"). Under a minute collapses to the
  *   "just now" key. Uses translated keys, not `Intl.RelativeTimeFormat`, so the exact
  *   wording is controlled by the `common:time.*` translation resources.
  */
-export function timeAgo(iso: string): string {
+export function timeAgo(iso: string, short = false): string {
   const ms = Date.now() - parseDate(iso).getTime();
   if (Number.isNaN(ms)) return "-";
+  // `short` drops the "ago" ("17m"), for a narrow column like the sidebar's.
+  const k = short ? "Short" : "";
   const seconds = Math.floor(ms / 1000);
-  if (seconds < 60) return i18n.t("common:time.justNow");
+  if (seconds < 60) return i18n.t(`common:time.justNow${k}`);
   const minutes = Math.floor(seconds / 60);
-  if (minutes < 60) return i18n.t("common:time.mAgo", { count: minutes });
+  if (minutes < 60) return i18n.t(`common:time.mAgo${k}`, { count: minutes });
   const hours = Math.floor(minutes / 60);
-  if (hours < 24) return i18n.t("common:time.hAgo", { count: hours });
+  if (hours < 24) return i18n.t(`common:time.hAgo${k}`, { count: hours });
   const days = Math.floor(hours / 24);
-  return i18n.t("common:time.dAgo", { count: days });
+  return i18n.t(`common:time.dAgo${k}`, { count: days });
 }
 
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