feat(cockpit): quick wins — sync chip, cost budget guard, digest, recent commits (W3)

Four small, high-delight features that turn passive capture into glanceable signals.

- Sync chip on project cards: ahead/behind vs upstream + last-commit time, folded
  into the existing concurrent per-repo metadata pass (git rev-list --count
  --left-right @{u}...HEAD + git log -1 --format=%ct; no upstream → undefined, no route).
- Cost budget guard: COST_BUDGET_USD env (0 = off); a per-session one-shot latch
  (Session.budgetNotified, cost is monotonic so never re-armed) fires a single push
  on threshold crossing in manager.handleStatusLine; the already-broadcast telemetry
  frame carries the warn (tg-cost-warn styling derived from costUsd>=budget via
  /config/ui — no new ServerMessage). web-push title added to sw-push.js.
- "While you were away" digest: GET /digest?since= → {finished, needsInput, stuck,
  totalCostUsd, sessions[]} aggregate over manager.list(); FE banner on reconnect.
- Recent commits per project: src/http/git-log.ts (NUL-delimited git log → CommitInfo[]),
  GET /projects/log?path= (isValidGitDir), textContent-inert render in project detail.

All git via execFile (no shell) + validated cwd; new routes read-only; commit
messages rendered via textContent. Verified: typecheck + build:web clean, 1904 pass
at --test-timeout=30000 (two default-5s failures are slow-sandbox real-subprocess
timeout flakes — the known ring-buffer test + a new real-git-clone sync test — not
logic regressions).

test/digest.test.ts

@@ -0,0 +1,165 @@
+// @vitest-environment jsdom
+/**
+ * test/digest.test.ts (W3 quick-wins c) — reconnect digest banner (public/digest.ts).
+ *
+ * Pure helpers (normalizeDigest / digestSummary / renderDigestBanner) + the
+ * mountDigest wiring with a mocked fetch: fetches with the stored last-seen,
+ * shows a banner only when something happened, dismiss advances last-seen + hides,
+ * and a fetch failure shows no banner (best-effort). localStorage comes from the
+ * shared jsdom polyfill (vitest.config setupFiles).
+ */
+
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest'
+import type { DigestResult } from '../src/types.js'
+import {
+  normalizeDigest,
+  digestSummary,
+  digestHighlightCount,
+  renderDigestBanner,
+  getLastSeen,
+  setLastSeen,
+  mountDigest,
+} from '../public/digest.js'
+
+function makeDigest(over: Partial<DigestResult> = {}): DigestResult {
+  return {
+    since: 0,
+    generatedAt: 5000,
+    total: 0,
+    finished: 0,
+    needsInput: 0,
+    stuck: 0,
+    working: 0,
+    totalCostUsd: 0,
+    sessions: [],
+    ...over,
+  }
+}
+
+/** Install a fetch mock returning `body` (or rejecting when `body` is null). */
+function mockFetch(body: unknown, ok = true): ReturnType<typeof vi.fn> {
+  const fn = vi.fn(async () => {
+    if (body === null) throw new Error('network down')
+    return { ok, json: async () => body } as Response
+  })
+  vi.stubGlobal('fetch', fn)
+  return fn
+}
+
+beforeEach(() => {
+  localStorage.clear()
+  document.body.innerHTML = ''
+})
+
+afterEach(() => {
+  vi.unstubAllGlobals()
+})
+
+// ── pure helpers ──────────────────────────────────────────────────────────────
+
+describe('normalizeDigest', () => {
+  it('returns null for a non-object / missing generatedAt', () => {
+    expect(normalizeDigest(null)).toBeNull()
+    expect(normalizeDigest('x')).toBeNull()
+    expect(normalizeDigest({ total: 1 })).toBeNull()
+  })
+
+  it('coerces a well-formed response', () => {
+    const d = normalizeDigest(makeDigest({ finished: 2, totalCostUsd: 1.5 }))
+    expect(d?.finished).toBe(2)
+    expect(d?.totalCostUsd).toBe(1.5)
+    expect(Array.isArray(d?.sessions)).toBe(true)
+  })
+
+  it('defaults missing numeric counts to 0 and non-array sessions to []', () => {
+    const d = normalizeDigest({ generatedAt: 10 })
+    expect(d?.finished).toBe(0)
+    expect(d?.sessions).toEqual([])
+  })
+})
+
+describe('digestSummary / digestHighlightCount', () => {
+  it('counts finished + needsInput + stuck', () => {
+    expect(digestHighlightCount(makeDigest({ finished: 2, needsInput: 1, stuck: 1, working: 9 }))).toBe(4)
+  })
+
+  it('builds a compact summary of only the non-zero buckets', () => {
+    const s = digestSummary(makeDigest({ finished: 2, stuck: 1 }))
+    expect(s).toContain('2 finished')
+    expect(s).toContain('1 stuck')
+    expect(s).not.toContain('waiting')
+  })
+})
+
+describe('renderDigestBanner', () => {
+  it('returns null when nothing worth showing', () => {
+    expect(renderDigestBanner(makeDigest({ working: 3 }), () => {})).toBeNull()
+  })
+
+  it('renders a dismissible banner and wires the × button', () => {
+    const onDismiss = vi.fn()
+    const banner = renderDigestBanner(makeDigest({ finished: 1 }), onDismiss)
+    expect(banner?.className).toContain('wya-banner')
+    ;(banner?.querySelector('.wya-dismiss') as HTMLButtonElement).click()
+    expect(onDismiss).toHaveBeenCalled()
+  })
+
+  it('renders an attacker-influenced summary as inert text (SEC-H5)', () => {
+    const banner = renderDigestBanner(makeDigest({ finished: 1 }), () => {})
+    expect(banner?.querySelectorAll('script').length).toBe(0)
+  })
+})
+
+describe('getLastSeen / setLastSeen', () => {
+  it('defaults to 0 and round-trips a value', () => {
+    expect(getLastSeen()).toBe(0)
+    setLastSeen(1234)
+    expect(getLastSeen()).toBe(1234)
+  })
+})
+
+// ── mountDigest (wiring) ──────────────────────────────────────────────────────
+
+describe('mountDigest', () => {
+  it('fetches with the stored last-seen watermark', async () => {
+    setLastSeen(500)
+    const fetchFn = mockFetch(makeDigest({ finished: 1 }))
+    await mountDigest(document.body)
+    expect(fetchFn).toHaveBeenCalledWith('/digest?since=500')
+  })
+
+  it('shows a banner when something happened', async () => {
+    mockFetch(makeDigest({ finished: 1 }))
+    await mountDigest(document.body)
+    expect(document.body.querySelector('.wya-banner')).not.toBeNull()
+  })
+
+  it('shows NO banner when nothing happened', async () => {
+    mockFetch(makeDigest({ working: 2 }))
+    await mountDigest(document.body)
+    expect(document.body.querySelector('.wya-banner')).toBeNull()
+  })
+
+  it('advances last-seen to generatedAt after a fetch', async () => {
+    mockFetch(makeDigest({ generatedAt: 8888, finished: 1 }))
+    await mountDigest(document.body)
+    expect(getLastSeen()).toBe(8888)
+  })
+
+  it('dismiss updates last-seen and removes the banner', async () => {
+    mockFetch(makeDigest({ generatedAt: 7777, needsInput: 1 }))
+    await mountDigest(document.body)
+    const banner = document.body.querySelector('.wya-banner')
+    expect(banner).not.toBeNull()
+    ;(banner!.querySelector('.wya-dismiss') as HTMLButtonElement).click()
+    expect(document.body.querySelector('.wya-banner')).toBeNull()
+    expect(getLastSeen()).toBe(7777)
+  })
+
+  it('shows no banner on a fetch failure (best-effort)', async () => {
+    mockFetch(null)
+    const banner = await mountDigest(document.body)
+    expect(banner).toBeNull()
+    expect(document.body.querySelector('.wya-banner')).toBeNull()
+  })
+})