feat(docker): restore in-app self-update in the Compose deployment

Codeman running under docker/docker-compose.yaml lost the ability to update
itself from App Settings -> Updates. The image had no .git (excluded by
.dockerignore), so the install reported as "unknown"; there was no init system
for detectSupervisor() to find; the runtime stage had neither devDependencies
nor a build toolchain; and a pull into the baked /opt/codeman would have landed
in the container's writable layer and been discarded by the next `up`.

Restore it through configuration rather than a second updater, so the release
channel, auto-stash, status file and boot reconcile are all reused unchanged:

- The checkout Compose builds from is bind-mounted over /opt/codeman, so the
  update's git checkout and rebuild land on the host and survive recreation.
- The restart is the server exiting; `restart: unless-stopped` relaunches the
  container on the new dist/. This is the one supervisor whose updater does NOT
  outlive the restart, which is safe only because the terminal "restarting"
  marker is written first.
- node_modules and dist are named volumes over the bind mount, so
  container-compiled native modules never enter the host checkout.
- The runtime image keeps devDependencies and gains python3/make/g++, since
  `npm run build` is tsc + esbuild and node-pty has no Linux prebuild.

An in-place container update applies code only, because a restart reuses the
existing image and config. evaluateEnvironmentGate() reads the target release's
own files with `git show <tag>:<path>` and refuses when server.Dockerfile or
docker-compose.yaml changed, when .env.example gained keys the user's .env
lacks, or when the restart policy would not bring the container back. The
missing-key check matters most: Compose resolves an unset ${VAR} to the empty
string and starts anyway, so a new required setting would otherwise arrive as a
silently blank variable. Every unknown fails open, and the gate is re-evaluated
server-side on POST /api/system/update.

The four global agent CLIs are pinned, because an unpinned CLI bump is the one
environment change no diff-derived gate can see; pinning turns it into a
Dockerfile change the gate already detects.

Adds test/docker-compose-env-parity.test.ts as the merge-side guard (every
compose ${VAR} has an .env.example entry and the reverse) and
test/docker-self-update.test.ts for the pure gate decisions.

Documented in docs/docker-self-update.md.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013yAQ2y9t81jzSfpStUxx5T

src/types/update.ts

@@ -7,6 +7,10 @@
  * (see `dataPath('update-status.json')`) that the browser polls across the
  * restart boundary.
  *
+ * The Docker Compose deployment updates in place too (same script, same status
+ * file) — see `docs/docker-self-update.md` for how the container restarts itself
+ * and what the environment gate refuses.
+ *
  * Backend logic: `src/web/self-update.ts`. Routes: `src/web/routes/system-routes.ts`
  * (`/api/system/update/check`, `POST /api/system/update`, `/api/system/update/status`).
  *
@@ -17,11 +21,56 @@
  * Which init system supervises the running server (decides how we restart it).
  * `launchd-daemon` = a KeepAlive system-level LaunchDaemon (headless Macs, no GUI
  * login): restart works by killing the server and letting launchd respawn it.
+ * `docker-compose` = the Compose deployment (`docker/docker-compose.yaml`): the
+ * "restart" is the server exiting so the container's `restart: unless-stopped`
+ * policy relaunches it on the freshly built `dist/`.
  */
-export type SupervisorKind = 'systemd' | 'launchd' | 'launchd-daemon' | 'none';
+export type SupervisorKind = 'systemd' | 'launchd' | 'launchd-daemon' | 'docker-compose' | 'none';
 
-/** How Codeman was installed — only `git` installs can self-update in place. */
-export type InstallKind = 'git' | 'npm' | 'unknown';
+/**
+ * How Codeman was installed. `git` and `docker-compose` can self-update in
+ * place; `docker-compose` is a git checkout bind-mounted into the container, so
+ * the pull/build happen on the host filesystem and survive container recreation.
+ */
+export type InstallKind = 'git' | 'docker-compose' | 'npm' | 'unknown';
+
+/**
+ * Why an in-place container update is refused. Each is derived mechanically from
+ * the target release's own files — nothing here depends on a human remembering
+ * to declare something at release time.
+ *
+ * - `dockerfile-changed` / `compose-changed`: the release changes the ENVIRONMENT,
+ *   which a self-restart cannot apply (a restart reuses the existing container's
+ *   image and config). Needs a rebuild + recreate from the host.
+ * - `env-keys-missing`: the release's `docker/.env.example` gained keys the user's
+ *   `docker/.env` has no value for. Compose interpolates an unset `${VAR}` to the
+ *   EMPTY STRING and starts anyway, so without this check a new required setting
+ *   arrives as a silently blank env var.
+ * - `no-auto-restart`: the container's restart policy would not bring it back
+ *   after the server exits, so applying the update would take Codeman down.
+ */
+export type EnvironmentBlockerKind = 'dockerfile-changed' | 'compose-changed' | 'env-keys-missing' | 'no-auto-restart';
+
+/** One reason an in-place container update is refused, with UI-ready text. */
+export interface EnvironmentBlocker {
+  kind: EnvironmentBlockerKind;
+  /** One-line explanation shown in App Settings → Updates. */
+  message: string;
+  /** Optional specifics (e.g. the names of the missing env keys). */
+  details?: string[];
+}
+
+/**
+ * Result of the environment gate for a candidate release. `checked: false` means
+ * the gate did not run (not a container install, or the target tag's files could
+ * not be read) — callers must not treat that as "no blockers".
+ */
+export interface EnvironmentGate {
+  checked: boolean;
+  blockers: EnvironmentBlocker[];
+  /** The host command that resolves every blocker. */
+  hostCommand: string;
+}
 
 /**
  * Lifecycle of a single update run. `idle`/`completed`/`failed`/
@@ -96,6 +145,8 @@ export interface UpdateCheckResult {
   /** epoch ms of the check. */
   checkedAt: number;
   source: 'github-api' | 'git-ls-remote' | 'none';
+  /** Environment gate for THIS candidate release (container installs only). */
+  environment?: EnvironmentGate;
   error?: string;
 }
 

src/web/public/settings-ui.js

@@ -1079,10 +1079,14 @@ Object.assign(CodemanApp.prototype, {
     const verEl = this.$('updateCurrentVersion');
     if (verEl && data.currentVersion) verEl.textContent = `v${data.currentVersion}`;
 
-    if (data.installKind && data.installKind !== 'git') {
-      this._setUpdateResult(
-        `This install can't update itself (${escapeHtml(data.installKind)}). Update with <code>npm i -g aicodeman@latest</code>.`
-      );
+    // `docker-compose` self-updates in place like `git` does — the container
+    // restarts itself. Anything else cannot.
+    if (data.installKind && data.installKind !== 'git' && data.installKind !== 'docker-compose') {
+      const hint =
+        data.supervisor === 'docker-compose'
+          ? 'Update from the Docker host with <code>docker/Start-Codeman.sh</code>.'
+          : 'Update with <code>npm i -g aicodeman@latest</code>.';
+      this._setUpdateResult(`This install can't update itself (${escapeHtml(data.installKind)}). ${hint}`);
       return;
     }
     if (data.selfUpdateEnabled === false) {
@@ -1093,6 +1097,30 @@ Object.assign(CodemanApp.prototype, {
       this._setUpdateResult(escapeHtml(data.error));
       return;
     }
+    // A container release that changes the ENVIRONMENT (Dockerfile, compose file
+    // or new .env keys) cannot be applied by the container restarting itself, so
+    // the update button is never offered — the host command is, instead. The
+    // server re-checks this on POST, so hiding the button is UX, not the gate.
+    const blockers = data.environment?.blockers || [];
+    if (data.updateAvailable && blockers.length > 0) {
+      const reasons = blockers
+        .map((b) => {
+          const details = b.details?.length ? `<br><code>${escapeHtml(b.details.join(' '))}</code>` : '';
+          return `<li>${escapeHtml(b.message)}${details}</li>`;
+        })
+        .join('');
+      this._setUpdateResult(
+        `<strong>v${escapeHtml(data.latestVersion || '')}</strong> needs a rebuild on the Docker host` +
+          ` (current v${escapeHtml(data.currentVersion || '')}):<ul>${reasons}</ul>` +
+          `Run <code>${escapeHtml(data.environment?.hostCommand || 'docker/Start-Codeman.sh')}</code> there to apply it.`
+      );
+      if (notes && data.notes) {
+        notes.style.display = 'block';
+        notes.textContent = data.notes;
+      }
+      return;
+    }
+
     if (data.updateAvailable && data.latestVersion) {
       this._setUpdateResult(
         `Update available: <strong>v${escapeHtml(data.latestVersion)}</strong> &nbsp;(current v${escapeHtml(data.currentVersion || '')})`

src/web/routes/system-routes.ts

@@ -389,6 +389,9 @@ export function registerSystemRoutes(
       'in-flight': { http: 409, api: ApiErrorCode.ALREADY_EXISTS },
       'up-to-date': { http: 409, api: ApiErrorCode.ALREADY_EXISTS },
       'not-git': { http: 400, api: ApiErrorCode.INVALID_INPUT },
+      // A container release that changes the ENVIRONMENT: not a client error to
+      // retry, it needs a host-side rebuild (docs/docker-self-update.md).
+      'env-blocked': { http: 409, api: ApiErrorCode.INVALID_INPUT },
       disabled: { http: 403, api: ApiErrorCode.INVALID_INPUT },
       'bad-tag': { http: 400, api: ApiErrorCode.INVALID_INPUT },
       error: { http: 500, api: ApiErrorCode.INTERNAL_ERROR },

src/web/self-update.ts

@@ -16,6 +16,15 @@
  * tested, and IO wrappers (`getInstallInfo`, `checkForUpdate`, `startUpdate`,
  * `reconcileUpdateOnBoot`) that touch git/network/fs.
  *
+ * DOCKER COMPOSE installs update in place too, through the same script and the
+ * same status file. The repo is a host bind mount, so the pull/build land on the
+ * host filesystem and survive container recreation; the "restart" is the server
+ * EXITING so the container's restart policy relaunches it on the new `dist/`.
+ * That applies CODE only — a restart reuses the existing container's image and
+ * config — so `evaluateEnvironmentGate()` refuses a release that changes
+ * `server.Dockerfile`, `docker-compose.yaml` or `.env.example`, pointing at the
+ * host command instead. See `docs/docker-self-update.md`.
+ *
  * Related: `src/types/update.ts`, `scripts/self-update.sh`, routes in
  * `src/web/routes/system-routes.ts`.
  *
@@ -26,13 +35,15 @@ import { spawn, execFileSync } from 'node:child_process';
 import { existsSync, readFileSync, writeFileSync, renameSync, copyFileSync, chmodSync } from 'node:fs';
 import { dirname, join } from 'node:path';
 import { fileURLToPath } from 'node:url';
-import { homedir, tmpdir } from 'node:os';
-import { randomUUID } from 'node:crypto';
+import { homedir, hostname, tmpdir } from 'node:os';
+import { randomUUID, createHash } from 'node:crypto';
 import { createRequire } from 'node:module';
 import { dataPath } from '../config/instance.js';
 import { LAUNCHD_LABEL, SYSTEMD_UNIT } from '../config/service-names.js';
 import { EXEC_TIMEOUT_MS } from '../config/exec-timeout.js';
 import type {
+  EnvironmentBlocker,
+  EnvironmentGate,
   InstallInfo,
   InstallKind,
   SupervisorKind,
@@ -215,6 +226,120 @@ export function reconcileStatusDecision(
   return null;
 }
 
+// ─────────────────────────────────────────────────────────────────────────────
+// PURE helpers — the container environment gate
+// ─────────────────────────────────────────────────────────────────────────────
+
+/** Host command that resolves every environment blocker. */
+export const DOCKER_HOST_UPDATE_COMMAND = 'docker/Start-Codeman.sh';
+
+/**
+ * Parse the SET keys out of a dotenv file. Commented-out lines are deliberately
+ * NOT keys: `docker/.env.example` uses `# PUID=1000` to document an OPTIONAL
+ * override, so treating those as required would block every update on settings
+ * the user is meant to leave alone.
+ */
+export function parseEnvKeys(text: string): string[] {
+  const keys: string[] = [];
+  for (const raw of text.split(/\r?\n/)) {
+    const line = raw.trim();
+    if (!line || line.startsWith('#')) continue;
+    const m = line.replace(/^export\s+/, '').match(/^([A-Za-z_][A-Za-z0-9_]*)\s*=/);
+    if (m && !keys.includes(m[1])) keys.push(m[1]);
+  }
+  return keys;
+}
+
+/**
+ * Keys the TARGET release's `.env.example` sets that the user's `.env` does not.
+ *
+ * This is the check that makes a new required setting visible: Compose resolves
+ * an unset `${VAR}` to the empty string and starts anyway, so a missing key is
+ * otherwise silent until something misbehaves at runtime.
+ */
+export function diffRequiredEnvKeys(targetExample: string, userEnv: string): string[] {
+  const have = new Set(parseEnvKeys(userEnv));
+  return parseEnvKeys(targetExample).filter((k) => !have.has(k));
+}
+
+/**
+ * True when the container's restart policy relaunches it after the server exits.
+ * `no` and an empty policy mean an in-place update would take Codeman DOWN
+ * rather than restart it, so the update is refused instead.
+ */
+export function isAutoRestartPolicy(name: string | null | undefined): boolean {
+  return name === 'always' || name === 'unless-stopped' || name === 'on-failure';
+}
+
+export interface EnvironmentGateInput {
+  /** sha256 of `docker/server.Dockerfile` the running container was built from. */
+  appliedDockerfileHash: string | null;
+  /** sha256 of `docker/server.Dockerfile` at the target release tag. */
+  targetDockerfileHash: string | null;
+  /** sha256 of `docker/docker-compose.yaml` the running container was created from. */
+  appliedComposeHash: string | null;
+  /** sha256 of `docker/docker-compose.yaml` at the target release tag. */
+  targetComposeHash: string | null;
+  /** Keys from `diffRequiredEnvKeys()`. */
+  missingEnvKeys: string[];
+  /** Docker restart policy name of the running container, or null if unknown. */
+  restartPolicy: string | null;
+}
+
+/**
+ * PURE gate decision. An in-place container update applies CODE only: the server
+ * exits and the container's restart policy relaunches it on the new `dist/`. A
+ * restart reuses the existing container's image and config, so anything that
+ * changes the ENVIRONMENT cannot take effect that way and is refused here with
+ * the host command that can apply it.
+ *
+ * ⚠️ An unknown hash (null) is NOT treated as "changed": a first update from a
+ * container created before the fingerprint file existed has no baseline, and
+ * failing closed there would block every such install from ever updating. The
+ * baseline is written by `Start-Codeman.sh`, so it exists from the first
+ * host-side start onward. An unknown restart policy is likewise not a blocker —
+ * the shipped Compose file sets `unless-stopped`, and the probe needs the Docker
+ * socket, which a user may not have mounted.
+ */
+export function computeEnvironmentBlockers(input: EnvironmentGateInput): EnvironmentBlocker[] {
+  const blockers: EnvironmentBlocker[] = [];
+
+  if (
+    input.appliedDockerfileHash &&
+    input.targetDockerfileHash &&
+    input.appliedDockerfileHash !== input.targetDockerfileHash
+  ) {
+    blockers.push({
+      kind: 'dockerfile-changed',
+      message: 'This release changes docker/server.Dockerfile, so the image must be rebuilt.',
+    });
+  }
+
+  if (input.appliedComposeHash && input.targetComposeHash && input.appliedComposeHash !== input.targetComposeHash) {
+    blockers.push({
+      kind: 'compose-changed',
+      message: 'This release changes docker/docker-compose.yaml, so the container must be recreated.',
+    });
+  }
+
+  if (input.missingEnvKeys.length > 0) {
+    blockers.push({
+      kind: 'env-keys-missing',
+      message: `This release adds ${input.missingEnvKeys.length} setting(s) your docker/.env has no value for.`,
+      details: input.missingEnvKeys,
+    });
+  }
+
+  if (input.restartPolicy !== null && !isAutoRestartPolicy(input.restartPolicy)) {
+    blockers.push({
+      kind: 'no-auto-restart',
+      message: `This container's restart policy is "${input.restartPolicy}", so it would not come back after the update.`,
+    });
+  }
+
+  return blockers;
+}
+
 // ─────────────────────────────────────────────────────────────────────────────
 // Status file IO
 // ─────────────────────────────────────────────────────────────────────────────
@@ -273,19 +398,149 @@ export function resolveInstallDir(): string {
   return process.cwd();
 }
 
+/**
+ * True when this process runs inside a container. `/.dockerenv` is created by the
+ * Docker daemon itself; the env var is set by our own Compose file so the check
+ * also holds under runtimes that omit that file.
+ */
+export function isRunningInContainer(): boolean {
+  return process.env.CODEMAN_IN_CONTAINER === '1' || existsSync('/.dockerenv');
+}
+
 function detectInstallKind(dir: string): InstallKind {
-  if (existsSync(join(dir, '.git'))) return 'git';
+  // A container whose code is a bind-mounted checkout updates in place (the pull
+  // and build land on the host filesystem and survive container recreation). A
+  // container WITHOUT that mount runs a baked image copy — a pull there would go
+  // to the writable layer and vanish on the next `up`, so it is not updatable.
+  if (existsSync(join(dir, '.git'))) return isRunningInContainer() ? 'docker-compose' : 'git';
   // Global npm install ships only dist/ (no src/, no .git).
   if (!existsSync(join(dir, 'src'))) return 'npm';
   return 'unknown';
 }
 
+/** Install kinds whose update is applied in place by `scripts/self-update.sh`. */
+export function canSelfUpdateInPlace(kind: InstallKind): boolean {
+  return kind === 'git' || kind === 'docker-compose';
+}
+
+/** Path of the fingerprint baseline written by `docker/Start-Codeman.sh`. */
+const DOCKER_ENV_APPLIED_FILE = dataPath('docker-env-applied.json');
+
+/** Files whose content defines the container ENVIRONMENT (vs. the app's code). */
+const DOCKERFILE_REL = 'docker/server.Dockerfile';
+const COMPOSE_REL = 'docker/docker-compose.yaml';
+const ENV_EXAMPLE_REL = 'docker/.env.example';
+const ENV_REL = 'docker/.env';
+
+function sha256(text: string): string {
+  return createHash('sha256').update(text, 'utf-8').digest('hex');
+}
+
+/** Read a file at a git TAG without checking it out (`git show tag:path`). */
+function gitShowAtTag(repo: string, tag: string, relPath: string): string | null {
+  return tryExec('git', ['show', `${tag}:${relPath}`], repo);
+}
+
+function readFileOrNull(path: string): string | null {
+  try {
+    return readFileSync(path, 'utf-8');
+  } catch {
+    return null;
+  }
+}
+
+/**
+ * The fingerprints the RUNNING container was created from, recorded on the host
+ * by `Start-Codeman.sh` at each build/recreate. Returns nulls when absent (a
+ * container started before this file existed) — `computeEnvironmentBlockers()`
+ * deliberately treats an unknown baseline as "not a blocker".
+ */
+function readAppliedEnvironmentFingerprints(): { dockerfile: string | null; compose: string | null } {
+  const raw = readFileOrNull(DOCKER_ENV_APPLIED_FILE);
+  if (!raw) return { dockerfile: null, compose: null };
+  try {
+    const parsed = JSON.parse(raw) as { dockerfileSha256?: string; composeSha256?: string };
+    return { dockerfile: parsed.dockerfileSha256 ?? null, compose: parsed.composeSha256 ?? null };
+  } catch {
+    return { dockerfile: null, compose: null };
+  }
+}
+
+/**
+ * Restart policy of the container we're running in, via the mounted Docker
+ * socket. Returns null when the socket or CLI is unavailable — an unknown policy
+ * is not a blocker (see `computeEnvironmentBlockers`).
+ */
+function detectOwnRestartPolicy(): string | null {
+  // Docker sets HOSTNAME to the short container id; os.hostname() is the same
+  // value when the env var is absent. A custom `hostname:` in the compose file
+  // makes both unresolvable to the daemon, which fails open (unknown is not a
+  // blocker) rather than refusing an update over a cosmetic setting.
+  const id = process.env.HOSTNAME || hostname();
+  if (!id) return null;
+  const out = tryExec('docker', ['inspect', '--format', '{{.HostConfig.RestartPolicy.Name}}', id]);
+  return out && out.length > 0 ? out : null;
+}
+
+/**
+ * Evaluate the environment gate for a candidate release tag. Reads the TARGET
+ * tag's files straight out of git (`git show`), so nothing is checked out and the
+ * answer is available at CHECK time — the UI can refuse before the user commits
+ * to an update.
+ */
+export function evaluateEnvironmentGate(installDir: string, tag: string): EnvironmentGate {
+  // `git show <tag>:<path>` needs the tag's objects locally, and neither the
+  // GitHub API nor `ls-remote` fetches anything — so a check that has never seen
+  // this tag would read nothing and report a falsely clean gate. Fetch the one
+  // ref first (cheap: it deltas against what the clone already has) and only
+  // then read. The updater fetches the same ref again; both are idempotent.
+  if (tryExec('git', ['rev-parse', '--verify', '--quiet', `${tag}^{commit}`], installDir) === null) {
+    tryExec(
+      'git',
+      ['fetch', '--tags', '--force', 'origin', `refs/tags/${tag}:refs/tags/${tag}`],
+      installDir,
+      CHECK_TIMEOUT_MS
+    );
+  }
+
+  const targetDockerfile = gitShowAtTag(installDir, tag, DOCKERFILE_REL);
+  const targetCompose = gitShowAtTag(installDir, tag, COMPOSE_REL);
+  const targetExample = gitShowAtTag(installDir, tag, ENV_EXAMPLE_REL);
+
+  // No environment files at the target tag at all: we cannot judge, so say so
+  // rather than reporting a clean gate the caller would trust.
+  if (targetDockerfile === null && targetCompose === null && targetExample === null) {
+    return { checked: false, blockers: [], hostCommand: DOCKER_HOST_UPDATE_COMMAND };
+  }
+
+  const applied = readAppliedEnvironmentFingerprints();
+  const userEnv = readFileOrNull(join(installDir, ENV_REL));
+
+  const blockers = computeEnvironmentBlockers({
+    appliedDockerfileHash: applied.dockerfile,
+    targetDockerfileHash: targetDockerfile === null ? null : sha256(targetDockerfile),
+    appliedComposeHash: applied.compose,
+    targetComposeHash: targetCompose === null ? null : sha256(targetCompose),
+    // A missing/unreadable .env cannot be diffed — report no missing keys rather
+    // than every key, which would block on an install using a non-standard path.
+    missingEnvKeys: targetExample !== null && userEnv !== null ? diffRequiredEnvKeys(targetExample, userEnv) : [],
+    restartPolicy: detectOwnRestartPolicy(),
+  });
+
+  return { checked: true, blockers, hostCommand: DOCKER_HOST_UPDATE_COMMAND };
+}
+
 /**
  * Detect which init system supervises us. Detection happens HERE (in the running
  * server, which has a rich env) and the result is passed to the updater script —
  * the detached child must not re-probe with a stripped-down environment.
  */
 export function detectSupervisor(): SupervisorKind {
+  // Checked FIRST: a container has no init system of its own, and its "restart"
+  // is the server exiting so the Docker restart policy relaunches it. Probing
+  // systemd here would find nothing and report `none`, which stages the update
+  // and then asks the user to restart by hand for no reason.
+  if (isRunningInContainer()) return 'docker-compose';
   if (process.platform === 'darwin') {
     if (existsSync(join(homedir(), 'Library', 'LaunchAgents', `${LAUNCHD_LABEL}.plist`))) return 'launchd';
     // Headless Macs (no GUI login → no gui domain) run Codeman as a system-level
@@ -389,17 +644,29 @@ export async function checkForUpdate(): Promise<UpdateCheckResult> {
     checkedAt,
     source: 'none',
   };
-  if (info.installKind !== 'git') {
-    return { ...base, error: 'Not a git install — self-update is unavailable.' };
+  if (!canSelfUpdateInPlace(info.installKind)) {
+    return {
+      ...base,
+      error:
+        info.installKind === 'unknown' && isRunningInContainer()
+          ? 'This container runs a baked image copy with no repository mounted — self-update is unavailable. See docs/docker-self-update.md.'
+          : 'Not a git install — self-update is unavailable.',
+    };
   }
 
+  /** Attach the container environment gate to a finished check result. */
+  const withGate = (result: UpdateCheckResult): UpdateCheckResult => {
+    if (info.installKind !== 'docker-compose' || !result.latestTag || !result.updateAvailable) return result;
+    return { ...result, environment: evaluateEnvironmentGate(info.installDir, result.latestTag) };
+  };
+
   const remote = tryExec('git', ['remote', 'get-url', 'origin'], info.installDir);
   const gh = remote ? parseGitHubRepo(remote) : null;
 
   if (gh) {
     const rel = await fetchLatestReleaseFromGitHub(gh.owner, gh.repo);
     if (rel) {
-      return {
+      return withGate({
         ...base,
         latestVersion: rel.version,
         latestTag: rel.tag,
@@ -407,20 +674,20 @@ export async function checkForUpdate(): Promise<UpdateCheckResult> {
         htmlUrl: rel.htmlUrl,
         updateAvailable: isNewerStableVersion(info.currentVersion, rel.version),
         source: 'github-api',
-      };
+      });
     }
   }
 
   // Fallback: enumerate remote tags directly (works for non-GitHub remotes too).
   const viaGit = fetchLatestTagViaGit(info.installDir);
   if (viaGit) {
-    return {
+    return withGate({
       ...base,
       latestVersion: viaGit.version,
       latestTag: viaGit.tag,
       updateAvailable: isNewerStableVersion(info.currentVersion, viaGit.version),
       source: 'git-ls-remote',
-    };
+    });
   }
 
   return { ...base, error: 'Could not reach the update server (GitHub API + git ls-remote both failed).' };
@@ -432,7 +699,11 @@ export async function checkForUpdate(): Promise<UpdateCheckResult> {
 
 export type StartUpdateResult =
   | { ok: true; updateId: string; toTag: string; toVersion: string | null }
-  | { ok: false; code: 'disabled' | 'not-git' | 'in-flight' | 'up-to-date' | 'bad-tag' | 'error'; message: string };
+  | {
+      ok: false;
+      code: 'disabled' | 'not-git' | 'in-flight' | 'up-to-date' | 'bad-tag' | 'env-blocked' | 'error';
+      message: string;
+    };
 
 /**
  * Copy the updater script OUT of the repo before running it. The script lives in
@@ -497,11 +768,13 @@ export async function startUpdate(): Promise<StartUpdateResult> {
   if (!info.selfUpdateEnabled) {
     return { ok: false, code: 'disabled', message: 'Self-update is disabled (CODEMAN_DISABLE_SELF_UPDATE=1).' };
   }
-  if (info.installKind !== 'git') {
+  if (!canSelfUpdateInPlace(info.installKind)) {
     return {
       ok: false,
       code: 'not-git',
-      message: 'This is not a git install. Update with: npm i -g aicodeman@latest',
+      message: isRunningInContainer()
+        ? 'This container has no repository mounted. Update from the host with docker/Start-Codeman.sh.'
+        : 'This is not a git install. Update with: npm i -g aicodeman@latest',
     };
   }
   const existing = readUpdateStatus();
@@ -517,6 +790,20 @@ export async function startUpdate(): Promise<StartUpdateResult> {
     return { ok: false, code: 'bad-tag', message: `Refusing to update to an unrecognized tag: ${check.latestTag}` };
   }
 
+  // Re-evaluate rather than trusting the check the browser saw: the UI hides the
+  // button when the gate blocks, but the endpoint is reachable directly and the
+  // release could have moved between the check and the click.
+  if (info.installKind === 'docker-compose') {
+    const gate = evaluateEnvironmentGate(info.installDir, check.latestTag);
+    if (gate.blockers.length > 0) {
+      return {
+        ok: false,
+        code: 'env-blocked',
+        message: `${gate.blockers.map((b) => b.message).join(' ')} Run ${gate.hostCommand} on the Docker host to apply this release.`,
+      };
+    }
+  }
+
   const prevSha = tryExec('git', ['rev-parse', 'HEAD'], info.installDir);
   const runner = stageRunner(info.installDir);
   if (!runner) {