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/__tests__/AlertsNotifications.spend.test.tsx

@@ -0,0 +1,102 @@
+/**
+ * @file Tests for the alert rule form's spend rules: a budget rule is built
+ * from period / limit / thresholds / AI tool (plus the browser's timezone
+ * offset), Preview shows what it would have fired without saving it, and
+ * Create saves the same config.
+ * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
+ */
+
+import { describe, it, expect, vi } from "vitest";
+import { render, screen } from "@testing-library/react";
+import { MemoryRouter } from "react-router-dom";
+import userEvent from "@testing-library/user-event";
+
+vi.mock("../../lib/api", () => ({
+  api: {
+    alerts: {
+      list: vi.fn().mockResolvedValue({ alerts: [], total: 0, unacked: 0, limit: 50, offset: 0 }),
+      rules: {
+        list: vi.fn().mockResolvedValue({ rules: [] }),
+        create: vi.fn().mockResolvedValue({ rule: {} }),
+        preview: vi.fn().mockResolvedValue({
+          supported: true,
+          window_days: 7,
+          fires: 1,
+          sessions: 0,
+          samples: [],
+          periods: [
+            {
+              period_start: "2026-09-01",
+              period_end: "2026-09-30",
+              spend: 120,
+              pct: 120,
+              crossed: [80, 100],
+            },
+            {
+              period_start: "2026-10-01",
+              period_end: "2026-10-31",
+              spend: 10,
+              pct: 10,
+              crossed: [],
+            },
+          ],
+        }),
+      },
+    },
+    aiTools: {
+      list: vi.fn().mockResolvedValue({
+        tools: [{ id: "codex", label: "Codex" }],
+        default: "claude",
+      }),
+    },
+  },
+}));
+
+import { api } from "../../lib/api";
+import { AlertsNotifications } from "../AlertsNotifications";
+
+describe("AlertsNotifications — spend rules", () => {
+  it("previews and creates a budget rule", async () => {
+    const user = userEvent.setup();
+    render(
+      <MemoryRouter>
+        <AlertsNotifications />
+      </MemoryRouter>
+    );
+    await user.click(await screen.findByText("Add rule"));
+    await user.type(screen.getByPlaceholderText("e.g. Error burst"), "Monthly");
+    const selects = screen.getAllByRole("combobox");
+    await user.selectOptions(selects[0]!, "budget");
+    await user.selectOptions(screen.getByDisplayValue("month"), "week");
+    const limit = screen.getByDisplayValue("100");
+    await user.clear(limit);
+    await user.type(limit, "50");
+    await screen.findByRole("option", { name: "Codex" });
+    await user.selectOptions(screen.getByDisplayValue("All AI tools"), "codex");
+
+    await user.click(screen.getByRole("button", { name: /Preview/ }));
+    const config = {
+      period: "week",
+      limit_usd: 50,
+      thresholds: [80, 100],
+      tz_offset: new Date().getTimezoneOffset(),
+      tool: "codex",
+    };
+    expect(api.alerts.rules.preview).toHaveBeenCalledWith({
+      rule_type: "budget",
+      config,
+      cooldown_seconds: 300,
+    });
+    expect(await screen.findByText("2026-09-01")).toBeInTheDocument();
+    expect(screen.getByText("80% 100%")).toBeInTheDocument();
+    expect(api.alerts.rules.create).not.toHaveBeenCalled();
+
+    await user.click(screen.getByRole("button", { name: /Create rule/ }));
+    expect(api.alerts.rules.create).toHaveBeenCalledWith({
+      name: "Monthly",
+      rule_type: "budget",
+      config,
+      cooldown_seconds: 300,
+    });
+  });
+});