feat: Claude Code Monitor — lanes, pipelines and a merged workspace

Internal SmartGift build of a Claude Code monitoring dashboard.

Lanes: a durable unit of parallel agent work, one per working directory,
tracked across session restarts. Managed lanes are git worktrees the
dashboard provisions and can reset or remove behind a three-check destroy
guard and a counted preflight; adopted lanes are directories you already
own and are never destroyable.

Pipelines: a lane moves through pipeline stages. A stage the agent declares
with evidence renders green; a stage inferred from the tool-event stream
renders dashed amber and never counts as done. Detection is forward-only
within a 30-minute window, and never writes the declared stage.

Workspace: one page at /run with a lane grid, the selected lane's pipeline,
and a full Claude console behind a disclosure.

desktop/src/logger.ts

@@ -0,0 +1,125 @@
+/**
+ * @file Lightweight file logger for the desktop shell.
+ *
+ * Electron's main process has no console attached when launched from Finder,
+ * so all diagnostics go to a per-user log file under app.getPath('logs').
+ * We deliberately avoid the `electron-log` dependency — the project keeps a
+ * small dependency tree and this file does the only three things we need.
+ * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
+ */
+/* =============================================================================
+ * MODULE_GUIDE — extended in-file reference (comments only; safe to read, never executed)
+ * =============================================================================
+ * **Purpose:** Dashboard module consumed by the React client, MCP tools, or desktop shell depending on deployment mode.
+ *
+ * ## Design constraints
+ * - Local-first: no telemetry leaves the machine unless the user configures webhooks.
+ * - Fail-safe hooks path on the server must never block Claude Code; UI mirrors that
+ *   philosophy by degrading gracefully (empty states, stale badges, reconnect loops).
+ * - Destructive flows stay behind explicit confirmation modals and server-side gates.
+ * - Internationalization: user-visible strings belong in i18n JSON, not literals here.
+ *
+ * ## Remote data & SSH
+ * Remote Data Sources let operators aggregate multiple machines. SSH entries describe
+ * how to reach a peer dashboard; the global data scope (`dataScope.ts`) narrows every
+ * scoped GET via `?sources=`. Health checks and import history surface in Settings.
+ *
+ * ## Observability
+ * Prometheus scrapes `GET /api/metrics` (see `monitoring/`). Grafana ships four
+ * provisioned boards (overview, sessions, tools, alerts). Native npm scripts and
+ * Docker Compose profiles are documented in `monitoring/README.md`.
+ *
+ * ## Public surface
+ * - `log` — exported API; see TSDoc on the symbol for behavior.
+ *
+ * ## Testing pointers
+ * - Prefer colocated `__tests__` with Vitest + Testing Library for UI.
+ * - Server contract changes require `npm run test:server` and OpenAPI sync.
+ * - MCP edits: `npm run mcp:typecheck` and `npm run mcp:build`.
+ *
+ * ## Related docs
+ * - `ARCHITECTURE.md` — hooks → API → SQLite → WebSocket → UI pipeline.
+ * - `docs/API.md` — REST reference.
+ * - `.claude/skills/file-headers/` — mandatory `@author` header policy.
+ * ============================================================================= */
+/* -----------------------------------------------------------------------------
+ * EXPORT CATALOG — quick index of symbols defined below (documentation only).
+ * -----------------------------------------------------------------------------
+ * **log**
+ *   Part of this module's public contract. Downstream imports should treat
+ *   the signature and return type as stable unless release notes say otherwise.
+ *   When behavior changes, update the `@file` overview and relevant tests.
+ *
+ * ----------------------------------------------------------------------------- */
+
+import { app } from "electron";
+import * as fs from "node:fs";
+import * as path from "node:path";
+
+let stream: fs.WriteStream | null = null;
+let logPath = "";
+
+/**
+ * Lazily open the append-mode write stream to `desktop.log`, creating the
+ * `app.getPath('logs')` directory if this is the first write of the process.
+ * Cached in the module-level `stream` so every subsequent `write()` call
+ * reuses the same file descriptor instead of re-opening the file.
+ */
+function ensureStream(): fs.WriteStream {
+  if (stream) return stream;
+  const dir = app.getPath("logs");
+  fs.mkdirSync(dir, { recursive: true });
+  logPath = path.join(dir, "desktop.log");
+  stream = fs.createWriteStream(logPath, { flags: "a" });
+  return stream;
+}
+
+/**
+ * Format one log line (ISO timestamp + level + space-joined parts) and fan it
+ * out to the log file and, conditionally, to the process streams:
+ *   - `error` always echoes to `stderr`, so a crash is visible even without
+ *     `CCAM_DESKTOP_VERBOSE` (e.g. when Electron is launched from a terminal).
+ *   - `info`/`warn` only echo to `stdout` when `CCAM_DESKTOP_VERBOSE` is set,
+ *     keeping a normal launch quiet.
+ * The file write is wrapped in try/catch — a logging failure (e.g. a full
+ * disk) must never take down the app.
+ */
+function write(level: "info" | "warn" | "error", parts: unknown[]): void {
+  const line = `${new Date().toISOString()} [${level}] ${parts
+    .map((p) => (typeof p === "string" ? p : safeStringify(p)))
+    .join(" ")}\n`;
+  try {
+    ensureStream().write(line);
+  } catch {
+    // Logging must never crash the app.
+  }
+  if (level === "error") {
+    process.stderr.write(line);
+  } else if (process.env.CCAM_DESKTOP_VERBOSE) {
+    process.stdout.write(line);
+  }
+}
+
+/** `JSON.stringify` a non-string log argument, falling back to `String()` for
+ * values it can't serialize (e.g. circular objects or `BigInt`). */
+function safeStringify(value: unknown): string {
+  try {
+    return JSON.stringify(value);
+  } catch {
+    return String(value);
+  }
+}
+
+/**
+ * The desktop shell's only logging surface. Electron's main process has no
+ * attached console when launched from Finder/Dock, so every call here is
+ * durably persisted to `desktop.log` (see `ensureStream`) in addition to the
+ * conditional stdout/stderr echo described in `write`.
+ */
+export const log = {
+  info: (...parts: unknown[]) => write("info", parts),
+  warn: (...parts: unknown[]) => write("warn", parts),
+  error: (...parts: unknown[]) => write("error", parts),
+  /** Absolute path to the active log file (populated after first write). */
+  path: () => logPath,
+};