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/integration/projects-log-endpoint.test.ts

@@ -0,0 +1,136 @@
+/**
+ * Integration test for GET /projects/log (W3 quick-wins d).
+ *
+ * Starts a real HTTP server, then asserts the recent-commit log route against a
+ * real temp git repo (3 commits): 200 + structured GitLogResult; missing path →
+ * 400; a non-git temp dir → 404 (isValidGitDir three-prong); ?n clamped.
+ */
+
+import fs from 'node:fs/promises'
+import net from 'node:net'
+import os from 'node:os'
+import path from 'node:path'
+import { execFile } from 'node:child_process'
+import { promisify } from 'node:util'
+
+import { afterAll, beforeAll, describe, expect, it } from 'vitest'
+
+import { loadConfig } from '../../src/config.js'
+import { startServer } from '../../src/server.js'
+import type { GitLogResult } from '../../src/types.js'
+
+const execFileAsync = promisify(execFile)
+
+function getFreePort(): Promise<number> {
+  return new Promise((resolve, reject) => {
+    const srv = net.createServer()
+    srv.listen(0, '127.0.0.1', () => {
+      const addr = srv.address()
+      if (addr === null || typeof addr === 'string') {
+        srv.close()
+        reject(new Error('unexpected address type'))
+        return
+      }
+      const port = addr.port
+      srv.close(() => resolve(port))
+    })
+    srv.on('error', reject)
+  })
+}
+
+async function git(cwd: string, ...args: string[]): Promise<void> {
+  await execFileAsync('git', args, { cwd })
+}
+
+async function gitAvailable(): Promise<boolean> {
+  try {
+    await execFileAsync('git', ['--version'])
+    return true
+  } catch {
+    return false
+  }
+}
+
+describe('GET /projects/log — integration', () => {
+  let port: number
+  let tmpRoot: string
+  let repoPath: string
+  let plainPath: string
+  let serverHandle: { close(): Promise<void> }
+  let haveGit = false
+
+  beforeAll(async () => {
+    haveGit = await gitAvailable()
+    port = await getFreePort()
+
+    tmpRoot = await fs.mkdtemp(path.join(os.tmpdir(), 'webterm-log-test-'))
+    repoPath = path.join(tmpRoot, 'repo')
+    plainPath = path.join(tmpRoot, 'plain')
+    await fs.mkdir(plainPath, { recursive: true })
+
+    if (haveGit) {
+      await fs.mkdir(repoPath, { recursive: true })
+      await git(repoPath, 'init', '-q', '-b', 'main')
+      await git(repoPath, 'config', 'user.email', 't@t.local')
+      await git(repoPath, 'config', 'user.name', 'tester')
+      await git(repoPath, 'config', 'commit.gpgsign', 'false')
+      for (const [file, msg] of [['a.txt', 'first'], ['b.txt', 'second'], ['c.txt', 'third']]) {
+        await fs.writeFile(path.join(repoPath, file), `${file}\n`)
+        await git(repoPath, 'add', '.')
+        await git(repoPath, 'commit', '-q', '-m', msg)
+      }
+    }
+
+    const cfg = loadConfig({
+      PORT: String(port),
+      BIND_HOST: '127.0.0.1',
+      SHELL_PATH: process.env['SHELL'] ?? '/bin/zsh',
+      ALLOWED_ORIGINS: `http://127.0.0.1:${port}`,
+      USE_TMUX: '0',
+      IDLE_TTL: '86400',
+    })
+    serverHandle = startServer(cfg)
+    await new Promise<void>((r) => setTimeout(r, 100))
+  })
+
+  afterAll(async () => {
+    await serverHandle.close()
+    await fs.rm(tmpRoot, { recursive: true, force: true })
+  })
+
+  it('returns 400 when path is missing', async () => {
+    const res = await fetch(`http://127.0.0.1:${port}/projects/log`)
+    expect(res.status).toBe(400)
+  })
+
+  it('returns 404 for a non-git directory (isValidGitDir three-prong)', async () => {
+    const res = await fetch(`http://127.0.0.1:${port}/projects/log?path=${encodeURIComponent(plainPath)}`)
+    expect(res.status).toBe(404)
+  })
+
+  it('returns 200 with the recent commits newest-first', async () => {
+    if (!haveGit) return
+    const res = await fetch(`http://127.0.0.1:${port}/projects/log?path=${encodeURIComponent(repoPath)}`)
+    expect(res.status).toBe(200)
+    const body = (await res.json()) as GitLogResult
+    expect(body.commits.map((c) => c.subject)).toEqual(['third', 'second', 'first'])
+  })
+
+  it('clamps ?n and flags truncated', async () => {
+    if (!haveGit) return
+    const res = await fetch(
+      `http://127.0.0.1:${port}/projects/log?path=${encodeURIComponent(repoPath)}&n=2`,
+    )
+    const body = (await res.json()) as GitLogResult
+    expect(body.commits).toHaveLength(2)
+    expect(body.truncated).toBe(true)
+
+    // A huge n must be clamped to ≤ 50 (never explodes) — here only 3 commits exist.
+    const res2 = await fetch(
+      `http://127.0.0.1:${port}/projects/log?path=${encodeURIComponent(repoPath)}&n=999`,
+    )
+    const body2 = (await res2.json()) as GitLogResult
+    expect(body2.commits.length).toBeLessThanOrEqual(50)
+    expect(body2.commits).toHaveLength(3)
+  })
+})