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/lib/__tests__/burnRate.test.ts

@@ -0,0 +1,26 @@
+/**
+ * @file Tests for spendPace — the 7-day burn rate, month to date and the
+ * month-end forecast built from the daily cost series.
+ * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
+ */
+import { describe, expect, it } from "vitest";
+import { spendPace } from "../burnRate";
+
+describe("spendPace", () => {
+  it("averages the last 7 days and carries the pace to month end", () => {
+    const daily = [
+      { date: "2026-09-28", cost: 70 }, // before the 7-day window (09-29..10-05)
+      { date: "2026-09-30", cost: 7 }, // inside the window, last month
+      { date: "2026-10-01", cost: 7 },
+      { date: "2026-10-05", cost: 14 },
+      { date: "2026-10-06", cost: 99 }, // after today: ignored
+    ];
+    const p = spendPace(daily, "2026-10-05");
+    expect(p.perDay7).toBe(4); // (7 + 7 + 14) / 7
+    expect(p.monthToDate).toBe(21);
+    expect(p.forecastMonth).toBe(21 + 4 * 26); // 26 days left in October
+  });
+  it("is all zero with no spend", () => {
+    expect(spendPace([], "2026-02-28")).toEqual({ perDay7: 0, monthToDate: 0, forecastMonth: 0 });
+  });
+});