feat: analytics parity — tool cost, date ranges, budgets, query explorer, replay, snapshots (v2.4.0)

Analytics parity phases 2–7 (docs/plans/analytics-parity/), built on
138e706 and ported onto v2.3.1:
- Cost by AI tool (?tool= on cost/analytics/stats/workflows, by_tool,
  Codex fast/priority and flex tiers, agenthub_cost_usd_total{tool,model})
- Date ranges (from/to) on cost/analytics/workflows; Analytics range select
  with Today / This week (Monday) / This month (1st) / 7d / 30d / 90d / All /
  Custom; workflow filters carried into workflow-stats.js (read worker)
- Budgets and cost alerts as alert rule types (alert_rules rebuilt without
  its rule_type CHECK), GET /api/budgets/status, rule preview, spend pace,
  status-bar budget chip; rules stay editable in place
- Query Explorer (/query, allowlisted sort, CSV/JSON export) and scheduled
  reports (report_definitions/report_runs, Settings → Reports)
- Session Replay tab and immutable snapshots (session_snapshots, /snapshot/:token)
- Remote Codex sync, push ingest with a hashed token, privacy redaction and
  ignored folders (Settings → Data), Cursor sessions (no cost)
- Read-only MCP server, statusline, Grafana/Prometheus files

Also: resizable sidebar, pet run/wave animations, the workspace home keeps a
half-typed prompt, and the pre-commit hook runs only the related tests for a
small commit.

client/src/components/Sagi/Sagi.tsx

@@ -203,6 +203,7 @@ export function Sagi() {
   const [open, setOpen] = useState(false);
   // The right-click pet menu (`PetMenu.tsx`).
   const [menu, setMenu] = useState(false);
+  const [hover, setHover] = useState(false);
   const reducedMotion = usePrefersReducedMotion();
   const navigate = useNavigate();
   const brain = useSagiBrain();
@@ -331,6 +332,8 @@ export function Sagi() {
         className="sagi-avatar-btn"
         data-dragging={place.dragging ? "1" : "0"}
         style={{ left: place.left, top: place.top, width: size, height: size }}
+        onPointerEnter={() => setHover(true)}
+        onPointerLeave={() => setHover(false)}
         onPointerDown={place.onPointerDown}
         onPointerMove={place.onPointerMove}
         onPointerUp={place.onPointerUp}
@@ -358,6 +361,8 @@ export function Sagi() {
             id={pet.id}
             kind={pet.kind}
             mood={brain.mood}
+            // Dragged → runs that way; hovered → waves (Codex's pet does both).
+            action={place.moving ? `run-${place.moving}` : hover ? "wave" : null}
             size={size}
             reducedMotion={reducedMotion}
             // Deleted elsewhere, or unreadable: back to Sagi.