feat(web): session detach/undock + beta instance isolation (port 5000)

CLAUDE.md

@@ -72,7 +72,7 @@ Codeman is a Claude Code session manager with web interface and autonomous Ralph
 
 ## Additional Commands
 
-`npm run dev` = dev server. Default port: `3000`. Commands not in Quick Reference:
+`npm run dev` = dev server. Default port: `5000` on this `beta/session-detach` branch (`3000` on master). Commands not in Quick Reference:
 
 | Task | Command |
 |------|---------|
@@ -98,6 +98,7 @@ Codeman is a Claude Code session manager with web interface and autonomous Ralph
 - **Dual-CLI prefix discipline** — Codeman supports both Claude Code and OpenCode (`claude-cli-resolver.ts` / `opencode-cli-resolver.ts`); env-var prefix is CLI-specific (`CLAUDE_CODE_*` vs `OPENCODE_*`) and the allowlist in `schemas.ts` enforces this. When adding settings, decide which CLI(s) it applies to and gate the env export accordingly — don't blindly forward both prefixes. See `docs/opencode-integration.md` for the OpenCode resolver design
 - **Zod `.optional()` rejects `null`** — accepts `undefined` only. When the frontend builds a request body with `JSON.stringify`, an explicit `null` field is preserved on the wire and fails validation with `INVALID_INPUT`. Convert `null` → `undefined` before stringifying (e.g. `field: value ?? undefined`), or declare the schema `.nullish()`. Real bugs caused: 0.6.4 (`durationMinutes` for ∞ respawn), and the same shape pattern hit `opusContext1mEnabled` in 0.6.3
 - **`xterm-zerolag-input` is duplicated** — the local-echo overlay lives in BOTH `packages/xterm-zerolag-input/src/` (published to npm as a standalone library for external consumers — see README "Published Packages") AND inline inside `src/web/public/app.js` (runtime copy the web UI actually loads, since the page ships as plain JS without a bundler). Any change to overlay behavior MUST be applied to both, or dev and prod diverge — and a public API break in the package warrants a separate version bump for `xterm-zerolag-input` in the changeset. Always test on mobile after touching it. See `docs/local-echo-overlay-plan.md`.
+- **Instance isolation / multi-instance attach danger** — data dir (`~/.codeman`) and tmux socket (`tmux -L codeman`) are PROCESS-WIDE and shared by every Codeman on the machine, derived from `CODEMAN_INSTANCE` via `src/config/instance.ts` (`getDataDir()`/`dataPath()`/`DEFAULT_TMUX_SOCKET`). ⚠️ A 2nd instance on the SAME socket **discovers and attaches PTYs to the first instance's live sessions** (`tmux -L codeman attach-session …`), resizing/mutating them — `$HOME` isolation is NOT enough (tmux is system-global). To run two instances, give each a distinct `CODEMAN_INSTANCE` (scopes BOTH dir+socket: `~/.codeman-<name>` + `-L codeman-<name>`), or set `CODEMAN_TMUX_SOCKET` + `CODEMAN_DATA_DIR` individually. **This `beta/session-detach` branch defaults to `CODEMAN_INSTANCE=beta` and port 5000** so it coexists with a prod Codeman out of the box. Any new `~/.codeman/...` path MUST go through `dataPath()`, never `join(homedir(), '.codeman', …)`.
 
 **Import conventions**: Utils from `./utils`, types from `./types` (barrel), config from specific `./config/*` files.
 

src/cli.ts

@@ -483,7 +483,7 @@ program
 program
   .command('web')
   .description('Start the web interface')
-  .option('-p, --port <port>', 'Port to listen on', '3000')
+  .option('-p, --port <port>', 'Port to listen on', '5000')
   .option('--https', 'Enable HTTPS with self-signed certificate (only needed for remote access, not localhost)')
   .option('--title-hostname <hostname>', 'Override the hostname shown in the browser title')
   .action(async (options) => {

src/config/instance.ts

@@ -0,0 +1,60 @@
+/**
+ * @fileoverview Per-instance isolation: data directory + tmux socket.
+ *
+ * Codeman keeps all runtime state under `~/.codeman` and runs its tmux sessions
+ * on a dedicated socket (`tmux -L codeman`). Both are PROCESS-WIDE and SHARED by
+ * every Codeman instance on the machine — so a second instance pointed at the
+ * same socket will discover and attach to the first instance's live sessions,
+ * and two instances sharing `~/.codeman/state.json` will clobber each other.
+ *
+ * To let a beta build coexist with a production one, this module derives both
+ * the data dir and the tmux socket from a single "instance" name:
+ *   - default (this branch): `beta` → `~/.codeman-beta` + `tmux -L codeman-beta`
+ *   - `CODEMAN_INSTANCE=`     (empty) → `~/.codeman`     + `tmux -L codeman`   (prod layout)
+ *   - `CODEMAN_INSTANCE=foo`          → `~/.codeman-foo`  + `tmux -L codeman-foo`
+ *
+ * Individual overrides still win: `CODEMAN_DATA_DIR` (absolute data dir) and
+ * `CODEMAN_TMUX_SOCKET` (socket name, validated in tmux-manager).
+ */
+
+import { homedir } from 'node:os';
+import { join } from 'node:path';
+import { mkdirSync } from 'node:fs';
+
+/**
+ * Instance name. Empty string = production layout (`~/.codeman`, `-L codeman`).
+ * Defaults to `beta` on the beta/session-detach branch so it never collides
+ * with a production Codeman. Set `CODEMAN_INSTANCE=` (empty) to opt back into
+ * the production layout.
+ */
+export const CODEMAN_INSTANCE = process.env.CODEMAN_INSTANCE ?? 'beta';
+
+const INSTANCE_SUFFIX = CODEMAN_INSTANCE ? `-${CODEMAN_INSTANCE}` : '';
+
+/** Default tmux socket for this instance. `CODEMAN_TMUX_SOCKET` still overrides. */
+export const DEFAULT_TMUX_SOCKET = `codeman${INSTANCE_SUFFIX}`;
+
+let _ensured = false;
+
+/**
+ * Absolute path to this instance's data directory (created on first use). All
+ * persisted state (`state.json`, `mux-sessions.json`, settings, push keys,
+ * lifecycle log, screenshots, certs, …) lives here.
+ */
+export function getDataDir(): string {
+  const dir = process.env.CODEMAN_DATA_DIR || join(homedir(), `.codeman${INSTANCE_SUFFIX}`);
+  if (!_ensured) {
+    try {
+      mkdirSync(dir, { recursive: true });
+      _ensured = true;
+    } catch {
+      /* best-effort; individual writers also mkdir as needed */
+    }
+  }
+  return dir;
+}
+
+/** Join one or more segments onto this instance's data directory. */
+export function dataPath(...segments: string[]): string {
+  return join(getDataDir(), ...segments);
+}

src/push-store.ts

@@ -8,12 +8,12 @@
 
 import { existsSync, readFileSync, writeFileSync, mkdirSync } from 'node:fs';
 import { join } from 'node:path';
-import { homedir } from 'node:os';
 import webpush from 'web-push';
 import type { VapidKeys, PushSubscriptionRecord } from './types.js';
 import { Debouncer } from './utils/index.js';
+import { getDataDir } from './config/instance.js';
 
-const DATA_DIR = join(homedir(), '.codeman');
+const DATA_DIR = getDataDir();
 const KEYS_FILE = join(DATA_DIR, 'push-keys.json');
 const SUBS_FILE = join(DATA_DIR, 'push-subscriptions.json');
 const SAVE_DEBOUNCE_MS = 500;

src/session-lifecycle-log.ts

@@ -10,9 +10,9 @@
 
 import { appendFile, readFile, writeFile } from 'node:fs/promises';
 import { existsSync, mkdirSync } from 'node:fs';
-import { dirname, join } from 'node:path';
-import { homedir } from 'node:os';
+import { dirname } from 'node:path';
 import type { LifecycleEventType, LifecycleEntry } from './types.js';
+import { dataPath } from './config/instance.js';
 
 const MAX_LINES = 10_000;
 const TRIM_TO = 8_000;
@@ -22,7 +22,7 @@ export class SessionLifecycleLog {
   private writeQueue: Promise<void> = Promise.resolve();
 
   constructor(filePath?: string) {
-    this.filePath = filePath || join(homedir(), '.codeman', 'session-lifecycle.jsonl');
+    this.filePath = filePath || dataPath('session-lifecycle.jsonl');
     const dir = dirname(this.filePath);
     if (!existsSync(dir)) {
       mkdirSync(dir, { recursive: true, mode: 0o700 });

src/state-store.ts

@@ -39,6 +39,7 @@ import {
   TokenUsageEntry,
 } from './types.js';
 import { Debouncer, MAX_SESSION_TOKENS } from './utils/index.js';
+import { dataPath, CODEMAN_INSTANCE } from './config/instance.js';
 
 /** Debounce delay for batching state writes (ms) */
 const SAVE_DEBOUNCE_MS = 500;
@@ -89,8 +90,10 @@ export class StateStore {
   private _saveInFlight: Promise<void> | null = null;
 
   constructor(filePath?: string) {
-    // Migrate legacy data directory (~/.claudeman → ~/.codeman)
-    if (!filePath) {
+    // Migrate legacy data directory (~/.claudeman → ~/.codeman). Default (prod)
+    // instance only — a named instance (e.g. beta) must never touch the shared
+    // ~/.codeman / ~/codeman-cases layout, preserving instance isolation.
+    if (!filePath && !CODEMAN_INSTANCE) {
       const legacyDir = join(homedir(), '.claudeman');
       const newDir = join(homedir(), '.codeman');
       if (existsSync(legacyDir) && !existsSync(newDir)) {
@@ -105,7 +108,7 @@ export class StateStore {
       }
     }
 
-    this.filePath = filePath || join(homedir(), '.codeman', 'state.json');
+    this.filePath = filePath || dataPath('state.json');
     this.ralphStatePath = this.filePath.replace('.json', '-inner.json');
     this.state = this.load();
     this.state.config.stateFilePath = this.filePath;

src/tmux-manager.ts

@@ -28,8 +28,8 @@ import { promisify } from 'node:util';
 const execAsync = promisify(exec);
 import { existsSync, readFileSync, mkdirSync } from 'node:fs';
 import { writeFile, rename } from 'node:fs/promises';
-import { dirname, join } from 'node:path';
-import { homedir } from 'node:os';
+import { dirname } from 'node:path';
+import { dataPath, DEFAULT_TMUX_SOCKET } from './config/instance.js';
 import {
   ProcessStats,
   PersistedRespawnConfig,
@@ -90,7 +90,7 @@ export const CLAUDE_CODE_NOFILE_LIMIT = 2147483646;
 const IS_TEST_MODE = !!process.env.VITEST;
 
 /** Path to persisted mux session metadata */
-const MUX_SESSIONS_FILE = join(homedir(), '.codeman', 'mux-sessions.json');
+const MUX_SESSIONS_FILE = dataPath('mux-sessions.json');
 
 /** Regex to validate tmux session names (only allow safe characters) */
 const SAFE_MUX_NAME_PATTERN = /^codeman-[a-f0-9-]+$/;
@@ -101,8 +101,9 @@ const LEGACY_MUX_NAME_PATTERN = /^claudeman-[a-f0-9-]+$/;
 /** Regex to validate tmux pane targets (e.g., "%0", "%1", "0", "1") */
 const SAFE_PANE_TARGET_PATTERN = /^(%\d+|\d+)$/;
 
-/** Dedicated tmux socket for new Codeman-owned sessions. */
-const DEFAULT_CODEMAN_TMUX_SOCKET = 'codeman';
+/** Dedicated tmux socket for new Codeman-owned sessions (instance-scoped:
+ *  `codeman` for prod, `codeman-beta` on the beta branch). */
+const DEFAULT_CODEMAN_TMUX_SOCKET = DEFAULT_TMUX_SOCKET;
 
 /** Regex to validate tmux socket names passed to `tmux -L`. */
 const SAFE_TMUX_SOCKET_PATTERN = /^[a-zA-Z0-9_.-]+$/;