diff --git a/README.md b/README.md
index c483a1d..3805ccb 100644
--- a/README.md
+++ b/README.md
@@ -176,8 +176,8 @@ Review the evidence in `fleet-proposal.json`, edit its `review.status` to
 `approved`, and identify the reviewer. Then inspect and apply the installation:
 
 ```bash
-node bin/torch.mjs install --proposal fleet-proposal.json --dry-run --json
-node bin/torch.mjs install --proposal fleet-proposal.json --yes --json
+node bin/torch.mjs install --proposal fleet-proposal.json --runtime claude --dry-run --json
+node bin/torch.mjs install --proposal fleet-proposal.json --runtime claude --yes --json
 node bin/torch.mjs doctor --json
 node bin/torch.mjs worktrees --dry-run --json
 node bin/torch.mjs worktrees --yes --json
@@ -189,10 +189,22 @@ step:
 
 ```bash
 node bin/torch.mjs up --fresh --yes --json
+node bin/torch.mjs up --only backend,qa --dry-run --json
+node bin/torch.mjs list --json
+node bin/torch.mjs brief --area backend --json
+node bin/torch.mjs capture --json
 node bin/torch.mjs down --dry-run --json
 node bin/torch.mjs down --yes --json
+node bin/torch.mjs detach --dry-run --json
+node bin/torch.mjs detach --yes --json
 ```
 
+`capture` externalizes the current stable identities, runtime IDs, presence,
+and worktree commits without stopping sessions. `detach` first enforces normal
+wind-down safety, then marks runtime integration detached while preserving the
+tracked organization, local state, branches, and worktrees. A later explicit
+`up` reattaches the selected runtime sessions.
+
 The Fleet can evolve when recurring work develops a coherent new boundary.
 The Session Manager may propose the domain through MCP or the CLI, but cannot
 approve or activate it. Owner approval and activation are deliberately
@@ -213,6 +225,19 @@ rejects silent ownership overlap, unknown checks/runtimes, worker-created
 roster changes, stale activation commits, and activation without matching
 owner approval.
 
+The manager can also submit evidence-backed boundary changes:
+
+```bash
+torch fleet propose-merge --from session-manager --proposal merge.json --json
+torch fleet propose-split --from session-manager --proposal split.json --json
+torch fleet reject --change <change-id> --by <owner> --reason "Not yet" --yes --json
+```
+
+Every existing owned-path pattern must be assigned exactly once. Approval
+records the owner's decision but does not activate a merge or split: TORCH
+returns a migration-required blocker until backlog, prompts, worktrees,
+branches, neighbours, and ownership transfer have a separately proven plan.
+
 The CLI fallback exposes `agents`, `who-owns`, `message`, `inbox`, `ack`,
 `status`, `complete`, `blocked`, `coordinate`, `handoff`, and the tracked
 `backlog` lifecycle. MCP hosts launch
@@ -280,9 +305,16 @@ torch schedules plan --id fleet-hygiene --actor session-manager --json
 torch schedules run --id fleet-hygiene --actor session-manager --json
 ```
 
-Mutating schedules additionally require `--yes`. Cron definitions are exposed
-for an external system launcher; TORCH does not silently install persistent
-timers.
+Mutating schedules additionally require `--yes`. TORCH can preview, install,
+inspect, and exactly remove its user-systemd launcher, but never installs the
+persistent timer implicitly:
+
+```bash
+torch schedules launcher plan --json
+torch schedules launcher install --yes --json
+torch schedules launcher status --json
+torch schedules launcher remove --yes --json
+```
 
 ## Product principles
 
diff --git a/reports/test-audit/test-integrity-note-2026-09-27-portable-kernel.yaml b/reports/test-audit/test-integrity-note-2026-09-27-portable-kernel.yaml
index 6dd28e5..ff45580 100644
--- a/reports/test-audit/test-integrity-note-2026-09-27-portable-kernel.yaml
+++ b/reports/test-audit/test-integrity-note-2026-09-27-portable-kernel.yaml
@@ -182,6 +182,14 @@ test_integrity_note:
       given: an installed Fleet and a file-backed proposed domain
       when: the manager proposes it and the owner separately approves, plans, and activates it through the public CLI
       then: missing approval is refused and the activated identity is queryable through the ordinary Fleet CLI
+    - id: SCN-cli-lifecycle-surface
+      given: an approved installed Fleet with isolated worktrees
+      when: an operator selects runtimes, previews selected startup, reads list and brief output, captures state, and detaches
+      then: the documented lifecycle commands share durable state, preserve the organization and worktrees, and require approval before stopping integrations
+    - id: SCN-install-runtime-selection
+      given: an approved Fleet proposal with declared runtime assignments
+      when: installation selects its enabled runtime adapters
+      then: unsupported or incomplete selections fail closed and the installed configuration contains the reviewed adapters
     - id: SCN-product-site
       given: the redesigned TORCH public surface
       when: its product story and local-console boundary are inspected
diff --git a/src/cli.mjs b/src/cli.mjs
index 9df72b6..39b53e1 100644
--- a/src/cli.mjs
+++ b/src/cli.mjs
@@ -19,7 +19,10 @@ import { readFileSync } from 'node:fs';
 import { resolve } from 'node:path';
 import { writeNewFile } from './kernel/files.mjs';
 import { createWorktrees, planWorktrees } from './kernel/worktrees.mjs';
-import { planAreaUp, planFleetDown, planFleetUp, startFleet, stopFleet } from './runtime/lifecycle.mjs';
+import {
+  captureFleet, createFleetBrief, detachFleet, planAreaUp, planFleetDetach,
+  planFleetDown, planFleetUp, startFleet, stopFleet,
+} from './runtime/lifecycle.mjs';
 import { ResourceService } from './resources/service.mjs';
 import { CANDIDATE_ACCEPTANCE_SCENARIOS, createVersionService } from './self-host/service.mjs';
 import { observeProject } from './observability/snapshot.mjs';
@@ -44,10 +47,14 @@ Usage:
   torch architect validate --brief <path> --response <path> [--json]
   torch architect run --brief <path> --provider <claude|codex> --output <path> [--model <model>] [--max-budget-usd <amount>] --yes [--json]
   torch domains [--repo <path>] [--spec <path>] [--output <path>] [--json]
-  torch install --proposal <path> [--dry-run] [--yes] [--json]
+  torch install --proposal <path> [--runtime <claude|codex|claude,codex>] [--dry-run] [--yes] [--json]
   torch worktrees [--parent <path>] [--dry-run] [--yes] [--json]
-  torch up [--fresh] [--dry-run] [--yes] [--json]
+  torch up [--fresh] [--only <id,id>] [--dry-run] [--yes] [--json]
   torch down [--dry-run] [--yes] [--json]
+  torch capture [--json]
+  torch detach [--dry-run] [--yes] [--json]
+  torch list [--json]
+  torch brief [--area <id>] [--json]
   torch identity --area <id> [--json]
   torch agents [--json]
   torch agent --area <id> [--json]
@@ -181,6 +188,25 @@ function runtimeAdapters() {
   ]);
 }
 
+function runtimeStoppers(spawn) {
+  return new Map([
+    ['claude', createClaudeAdapter({
+      runner: (executable, args) => spawn(executable, args, {
+        encoding: 'utf8', stdio: ['ignore', 'pipe', 'pipe'],
+      }),
+    })],
+    ['codex', createCodexAdapter()],
+  ]);
+}
+
+function stopThrough(adapters, action) {
+  const adapter = adapters.get(action.runtime);
+  if (!adapter) throw new TorchError(`No runtime stopper for ${action.runtime}`, {
+    code: 'RUNTIME_ADAPTER_MISSING', details: { runtime: action.runtime },
+  });
+  return adapter.stopSession({ runtimeSessionId: action.runtimeSessionId });
+}
+
 function runCandidateAcceptance(candidateRoot, spawn) {
   const checks = [
     { id: 'test', args: ['test'] },
@@ -204,6 +230,7 @@ function runCandidateAcceptance(candidateRoot, spawn) {
     ['ai-fleet-planning', ['SCN-ai-fleet-planning']],
     ['fleet-evolution', ['SCN-fleet-evolution', 'SCN-cli-fleet-evolution']],
     ['fleet-boundary-evolution', ['SCN-fleet-boundary-evolution']],
+    ['cli-lifecycle-surface', ['SCN-cli-lifecycle-surface']],
     ['review-install-roster', ['SCN-cli-domain-review']],
     ['branches-worktrees', ['SCN-worktree-bootstrap']],
     ['runtime-identities', ['SCN-mixed-runtime']],
@@ -439,9 +466,11 @@ export async function runCli(argv = process.argv.slice(2), {
     }
     if (command === 'install') {
       const proposalPath = optionValue(argv, '--proposal');
+      const runtimeOption = optionValue(argv, '--runtime');
+      const runtimes = runtimeOption === undefined ? undefined : commaList(runtimeOption);
       if (argv.includes('--dry-run')) {
         const proposal = loadProposal(cwd, proposalPath);
-        print({ ...planInstall({ repository, proposal, env }), proposal: resolve(cwd, proposalPath) }, { json });
+        print({ ...planInstall({ repository, proposal, env, runtimes }), proposal: resolve(cwd, proposalPath) }, { json });
         return 0;
       }
       if (!argv.includes('--yes')) {
@@ -450,7 +479,7 @@ export async function runCli(argv = process.argv.slice(2), {
         });
       }
       const proposal = loadProposal(cwd, proposalPath);
-      print(installProject({ repository, proposal, env }), { json });
+      print(installProject({ repository, proposal, env, runtimes }), { json });
       return 0;
     }
     if (command === 'doctor') {
@@ -479,6 +508,7 @@ export async function runCli(argv = process.argv.slice(2), {
         const adapters = runtimeAdapters();
         const plan = planFleetUp({
           repositoryRoot: repository.root, controlPlane: control, adapters, fresh: argv.includes('--fresh'),
+          only: optionValue(argv, '--only') === undefined ? undefined : commaList(optionValue(argv, '--only')),
         });
         if (argv.includes('--dry-run')) {
           print(plan, { json });
@@ -514,18 +544,40 @@ export async function runCli(argv = process.argv.slice(2), {
             code: 'APPROVAL_REQUIRED',
           });
         }
-        const runtimeStoppers = new Map([
-          ['claude', createClaudeAdapter({
-          runner: (executable, args) => spawn(executable, args, {
-            encoding: 'utf8', stdio: ['ignore', 'pipe', 'pipe'],
-          }),
-          })],
-          ['codex', createCodexAdapter()],
-        ]);
+        const stoppers = runtimeStoppers(spawn);
         print(stopFleet({
           plan, controlPlane: control,
-          stopRuntime: (action) => runtimeStoppers.get(action.runtime)
-            .stopSession({ runtimeSessionId: action.runtimeSessionId }),
+          stopRuntime: (action) => stopThrough(stoppers, action),
+        }), { json });
+        return 0;
+      } finally {
+        control.close();
+      }
+    }
+    if (command === 'capture') {
+      print(withControlPlane(repository, env, (control) => captureFleet({
+        repositoryRoot: repository.root, controlPlane: control,
+      })), { json });
+      return 0;
+    }
+    if (command === 'detach') {
+      const control = openControlPlane({ repositoryRoot: repository.root, env });
+      try {
+        const stoppers = runtimeStoppers(spawn);
+        const plan = planFleetDetach({
+          repositoryRoot: repository.root, controlPlane: control, adapters: stoppers,
+        });
+        if (argv.includes('--dry-run')) {
+          print(plan, { json });
+          return plan.canProceed ? 0 : 1;
+        }
+        if (!argv.includes('--yes')) {
+          throw new TorchError('Fleet detach stops runtime sessions while preserving organization and worktrees. Review --dry-run, then use --yes.', {
+            code: 'APPROVAL_REQUIRED',
+          });
+        }
+        print(detachFleet({
+          plan, controlPlane: control, stopRuntime: (action) => stopThrough(stoppers, action),
         }), { json });
         return 0;
       } finally {
@@ -536,10 +588,16 @@ export async function runCli(argv = process.argv.slice(2), {
       print(withControlPlane(repository, env, (control) => control.identity(optionValue(argv, '--area'))), { json });
       return 0;
     }
-    if (command === 'agents') {
+    if (command === 'agents' || command === 'list') {
       print(withControlPlane(repository, env, (control) => ({ agents: control.listAgents() })), { json });
       return 0;
     }
+    if (command === 'brief') {
+      print(withControlPlane(repository, env, (control) => createFleetBrief({
+        repositoryRoot: repository.root, controlPlane: control, areaId: optionValue(argv, '--area'),
+      })), { json });
+      return 0;
+    }
     if (command === 'agent') {
       print(withControlPlane(repository, env, (control) => control.getAgent(optionValue(argv, '--area'))), { json });
       return 0;
diff --git a/src/kernel/doctor.mjs b/src/kernel/doctor.mjs
index eb5f42d..83dd837 100644
--- a/src/kernel/doctor.mjs
+++ b/src/kernel/doctor.mjs
@@ -48,6 +48,18 @@ export function diagnoseProject({ repository, env = process.env }) {
     }
     const stateRoot = expectedStateRoot;
     if (!existsSync(stateRoot)) findings.push({ severity: 'error', code: 'LOCAL_STATE_MISSING', path: stateRoot });
+    const projectMetadataPath = join(stateRoot, 'project.json');
+    if (existsSync(projectMetadataPath)) {
+      try {
+        const metadata = parseJsonYaml(projectMetadataPath);
+        if (metadata.detachedAt) findings.push({
+          severity: 'info', code: 'FLEET_DETACHED', detachedAt: metadata.detachedAt,
+          recommendation: 'Run torch up after reviewing its dry-run plan to attach runtime integrations again.',
+        });
+      } catch (error) {
+        findings.push({ severity: 'error', code: 'LOCAL_STATE_METADATA_INVALID', message: error.message });
+      }
+    }
     const databasePath = join(stateRoot, 'state.db');
     if (existsSync(databasePath)) {
       try {
diff --git a/src/kernel/install.mjs b/src/kernel/install.mjs
index 431597b..3f3b082 100644
--- a/src/kernel/install.mjs
+++ b/src/kernel/install.mjs
@@ -16,7 +16,34 @@ function jsonYaml(value) {
   return `${JSON.stringify(value, null, 2)}\n`;
 }
 
-function initialFiles({ repository, projectId, createdAt, proposal }) {
+const RUNTIME_DEFINITIONS = Object.freeze({
+  claude: { model: 'opus', background: true },
+  codex: { sandbox: 'workspace-write', approval: 'approve-for-me' },
+});
+
+function resolveInstallRuntimes(proposal, requested) {
+  const selected = requested === undefined
+    ? Object.keys(RUNTIME_DEFINITIONS)
+    : [...new Set(requested)];
+  if (!selected.length || selected.some((runtime) => typeof runtime !== 'string' || !RUNTIME_DEFINITIONS[runtime])) {
+    throw new TorchError('Install runtimes must be one or more supported adapters', {
+      code: 'INSTALL_RUNTIME_INVALID', details: { requested: selected, supported: Object.keys(RUNTIME_DEFINITIONS) },
+    });
+  }
+  const required = new Set([
+    proposal.session_manager?.runtime ?? 'claude',
+    ...proposal.domains.map((domain) => domain.runtime ?? 'claude'),
+  ]);
+  const missing = [...required].filter((runtime) => !selected.includes(runtime));
+  if (missing.length) {
+    throw new TorchError('Selected install runtimes do not cover the approved Fleet', {
+      code: 'INSTALL_RUNTIME_MISSING', details: { selected, required: [...required], missing },
+    });
+  }
+  return selected;
+}
+
+function initialFiles({ repository, projectId, createdAt, proposal, runtimes }) {
   const promptContent = (source, fallback) => source
     ? readFileSync(safeProjectPath(repository.root, source), 'utf8')
     : fallback;
@@ -40,11 +67,10 @@ function initialFiles({ repository, projectId, createdAt, proposal }) {
       allow_force_push: false, allow_bare_stash: false,
     },
     synchronization: { strategy: 'dispatcher-managed', auto_merge_worktrees: false },
-    runtimes: {
-      default: 'claude',
-      claude: { model: 'opus', background: true },
-      codex: { sandbox: 'workspace-write', approval: 'approve-for-me' },
-    },
+    runtimes: Object.fromEntries([
+      ['default', proposal.session_manager?.runtime ?? 'claude'],
+      ...runtimes.map((runtime) => [runtime, RUNTIME_DEFINITIONS[runtime]]),
+    ]),
     checks: proposal.checks ?? [],
     resources: proposal.resources ?? [],
     schedules: proposal.schedules ?? [],
@@ -174,8 +200,9 @@ function safeProjectPath(root, relativePath) {
   return target;
 }
 
-export function planInstall({ repository, proposal, env = process.env }) {
+export function planInstall({ repository, proposal, env = process.env, runtimes: requestedRuntimes } = {}) {
   validateApprovedProposal({ proposal, repository });
+  const runtimes = resolveInstallRuntimes(proposal, requestedRuntimes);
   const trackedRoot = join(repository.root, TRACKED_DIR);
   return {
     action: 'install',
@@ -184,6 +211,7 @@ export function planInstall({ repository, proposal, env = process.env }) {
     stateParent: join(projectStatePath('<new-project-id>', env), '..'),
     wouldCreateTrackedState: !existsSync(trackedRoot),
     approvedDomainCount: proposal.domains.length,
+    runtimes,
     mutationPerformed: false,
   };
 }
@@ -194,8 +222,10 @@ export function installProject({
   env = process.env,
   projectId = randomUUID(),
   now = () => new Date(),
+  runtimes: requestedRuntimes,
 } = {}) {
   validateApprovedProposal({ proposal, repository });
+  const runtimes = resolveInstallRuntimes(proposal, requestedRuntimes);
   const trackedRoot = join(repository.root, TRACKED_DIR);
   if (existsSync(trackedRoot)) {
     throw new TorchError(`Refusing to replace existing ${trackedRoot}`, {
@@ -213,7 +243,7 @@ export function installProject({
 
   const created = [];
   try {
-    for (const [path, content] of initialFiles({ repository, projectId, createdAt, proposal })) {
+    for (const [path, content] of initialFiles({ repository, projectId, createdAt, proposal, runtimes })) {
       const absolute = join(trackedRoot, path);
       const record = writeNewFile(absolute, content);
       created.push({ path: relative(repository.root, record.path), sha256: record.sha256 });
diff --git a/src/runtime/lifecycle.mjs b/src/runtime/lifecycle.mjs
index 1429860..70ec28e 100644
--- a/src/runtime/lifecycle.mjs
+++ b/src/runtime/lifecycle.mjs
@@ -1,5 +1,5 @@
 import { execFileSync } from 'node:child_process';
-import { mkdirSync, readFileSync, renameSync, writeFileSync } from 'node:fs';
+import { existsSync, mkdirSync, readFileSync, renameSync, writeFileSync } from 'node:fs';
 import { dirname, join } from 'node:path';
 import { TorchError } from '../kernel/errors.mjs';
 import { readInstallManifest } from '../kernel/install.mjs';
@@ -23,6 +23,24 @@ function orderedAreas(roster) {
     ...roster.areas.filter((area) => area.id === 'session-manager')];
 }
 
+function selectedAreas(roster, only, blockers) {
+  const ordered = orderedAreas(roster);
+  if (only === undefined) return ordered;
+  const selected = Array.isArray(only)
+    ? [...new Set(only.map((id) => typeof id === 'string' ? id.trim() : '').filter(Boolean))]
+    : [];
+  if (!selected.length) {
+    blockers.push({ code: 'FLEET_SELECTION_EMPTY' });
+    return [];
+  }
+  const known = new Set(ordered.map((area) => area.id));
+  for (const areaId of selected.filter((id) => !known.has(id))) {
+    blockers.push({ areaId, code: 'FLEET_IDENTITY_MISSING' });
+  }
+  const wanted = new Set(selected);
+  return ordered.filter((area) => wanted.has(area.id));
+}
+
 function adapterMap({ adapter, adapters } = {}) {
   if (adapters instanceof Map) return adapters;
   if (adapters && typeof adapters === 'object') return new Map(Object.entries(adapters));
@@ -64,6 +82,24 @@ function atomicJson(path, value) {
   renameSync(temporary, path);
 }
 
+function projectMetadata(stateRoot) {
+  const path = join(stateRoot, 'project.json');
+  if (!existsSync(path)) throw new TorchError('TORCH local project metadata is missing', { code: 'LOCAL_STATE_MISSING' });
+  try { return { path, value: JSON.parse(readFileSync(path, 'utf8')) }; } catch (error) {
+    throw new TorchError('TORCH local project metadata is invalid', { code: 'LOCAL_STATE_INVALID', details: error.message });
+  }
+}
+
+function captureSnapshot({ plan, controlPlane, now = () => new Date() }) {
+  const snapshotPath = join(plan.stateRoot, 'sessions', 'resume.json');
+  atomicJson(snapshotPath, {
+    schema: 'torch.dev/runtime-snapshot/v1alpha1', projectId: plan.projectId,
+    capturedAt: now().toISOString(), agents: controlPlane.listAgents(),
+    worktrees: plan.actions.map((action) => action.worktree).filter(Boolean),
+  });
+  return snapshotPath;
+}
+
 function inspectWorktree(worktree) {
   const git = (args) => execFileSync('git', ['-C', worktree.path, ...args], { encoding: 'utf8' }).trim();
   return {
@@ -75,16 +111,16 @@ function inspectWorktree(worktree) {
   };
 }
 
-export function planFleetUp({ repositoryRoot, controlPlane, adapter, adapters, fresh = false } = {}) {
+export function planFleetUp({ repositoryRoot, controlPlane, adapter, adapters, fresh = false, only } = {}) {
   const { config, roster } = loadFleetDefinition(repositoryRoot);
   const manifest = readInstallManifest(repositoryRoot);
   const worktrees = worktreesByArea(manifest);
   const stateRoot = localStateRoot(manifest);
   const runtimes = adapterMap({ adapter, adapters });
-  const actions = [];
   const blockers = [];
+  const actions = [];
 
-  for (const area of orderedAreas(roster)) {
+  for (const area of selectedAreas(roster, only, blockers)) {
     const worktree = worktrees.get(area.id);
     if (!worktree) {
       blockers.push({ areaId: area.id, code: 'WORKTREE_MISSING' });
@@ -129,7 +165,8 @@ export function planFleetUp({ repositoryRoot, controlPlane, adapter, adapters, f
   }
 
   return {
-    action: 'fleet-up', projectId: manifest.projectId, fresh, actions, blockers,
+    action: 'fleet-up', projectId: manifest.projectId, stateRoot, fresh,
+    only: only ?? null, actions, blockers,
     canProceed: blockers.length === 0, mutationPerformed: false,
   };
 }
@@ -258,6 +295,12 @@ export function startFleet({ plan, controlPlane, executor, adapters } = {}) {
     });
     started.push({ areaId: action.areaId, runtimeSessionId: identity.runtimeSessionId, mode: action.mode });
   }
+  if (plan.stateRoot) {
+    const metadata = projectMetadata(plan.stateRoot);
+    if (metadata.value.detachedAt) {
+      atomicJson(metadata.path, { ...metadata.value, detachedAt: null, attachedAt: new Date().toISOString() });
+    }
+  }
   return { projectId: plan.projectId, started, mutationPerformed: true };
 }
 
@@ -328,11 +371,59 @@ export function stopFleet({ plan, controlPlane, stopRuntime, now = () => new Dat
     controlPlane.reportStatus({ areaId: action.areaId, state: 'offline', summary: 'Runtime stopped cleanly.' });
     stopped.push({ areaId: action.areaId, runtimeSessionId: action.runtimeSessionId, alreadyOffline: false });
   }
-  const snapshotPath = join(plan.stateRoot, 'sessions', 'resume.json');
-  atomicJson(snapshotPath, {
-    schema: 'torch.dev/runtime-snapshot/v1alpha1', projectId: plan.projectId,
-    capturedAt: now().toISOString(), agents: controlPlane.listAgents(),
-    worktrees: plan.actions.map((action) => action.worktree).filter(Boolean),
-  });
+  const snapshotPath = captureSnapshot({ plan, controlPlane, now });
   return { projectId: plan.projectId, stopped, snapshotPath, mutationPerformed: true };
 }
+
+export function captureFleet({ repositoryRoot, controlPlane, now = () => new Date() } = {}) {
+  const plan = planFleetDown({ repositoryRoot, controlPlane });
+  const snapshotPath = captureSnapshot({ plan, controlPlane, now });
+  return {
+    action: 'capture', projectId: plan.projectId, snapshotPath,
+    agents: controlPlane.listAgents(), mutationPerformed: true,
+  };
+}
+
+export function createFleetBrief({ repositoryRoot, controlPlane, areaId } = {}) {
+  const { roster } = loadFleetDefinition(repositoryRoot);
+  const selected = areaId
+    ? roster.areas.filter((area) => area.id === areaId)
+    : orderedAreas(roster);
+  if (!selected.length) {
+    throw new TorchError(`Unknown Fleet identity: ${areaId}`, { code: 'UNKNOWN_FLEET_IDENTITY' });
+  }
+  const commonPath = join(repositoryRoot, '.torch', 'prompts', 'COMMON.md');
+  const common = readFileSync(commonPath, 'utf8').trimEnd();
+  return {
+    schema: 'torch.dev/fleet-brief/v1alpha1', mutationPerformed: false,
+    areas: selected.map((area) => {
+      const promptPath = join(repositoryRoot, '.torch', 'prompts', `${area.id}.md`);
+      return {
+        areaId: area.id, title: area.title, identity: controlPlane.identity(area.id),
+        promptSources: [commonPath, promptPath],
+        prompt: `${common}\n\n${readFileSync(promptPath, 'utf8').trimEnd()}\n`,
+      };
+    }),
+  };
+}
+
+export function planFleetDetach({ repositoryRoot, controlPlane, adapters } = {}) {
+  const plan = planFleetDown({ repositoryRoot, controlPlane, adapters });
+  return { ...plan, action: 'fleet-detach' };
+}
+
+export function detachFleet({ plan, controlPlane, stopRuntime, now = () => new Date() } = {}) {
+  if (plan?.action !== 'fleet-detach') {
+    throw new TorchError('Fleet detach requires a reviewed detach plan', { code: 'FLEET_DETACH_PLAN_REQUIRED' });
+  }
+  const stopped = stopFleet({ plan, controlPlane, stopRuntime, now });
+  const metadata = projectMetadata(plan.stateRoot);
+  const detachedAt = now().toISOString();
+  atomicJson(metadata.path, { ...metadata.value, detachedAt });
+  return {
+    action: 'fleet-detach', projectId: plan.projectId, detachedAt,
+    stopped: stopped.stopped, snapshotPath: stopped.snapshotPath,
+    preserved: ['tracked organization', 'worktrees', 'branches', 'local state'],
+    mutationPerformed: true,
+  };
+}
diff --git a/src/self-host/service.mjs b/src/self-host/service.mjs
index 6720346..8d10fa7 100644
--- a/src/self-host/service.mjs
+++ b/src/self-host/service.mjs
@@ -14,6 +14,7 @@ export const CANDIDATE_ACCEPTANCE_SCENARIOS = Object.freeze([
   'ai-fleet-planning',
   'fleet-evolution',
   'fleet-boundary-evolution',
+  'cli-lifecycle-surface',
   'review-install-roster',
   'branches-worktrees',
   'runtime-identities',
diff --git a/test/fleet/cli-scenarios.test.mjs b/test/fleet/cli-scenarios.test.mjs
index 52c9d52..53796f5 100644
--- a/test/fleet/cli-scenarios.test.mjs
+++ b/test/fleet/cli-scenarios.test.mjs
@@ -37,6 +37,7 @@ function releaseCandidate(root, version) {
     'SCN-ai-fleet-planning',
     'SCN-fleet-evolution', 'SCN-cli-fleet-evolution',
     'SCN-fleet-boundary-evolution',
+    'SCN-cli-lifecycle-surface',
     'SCN-durable-message', 'SCN-ownership-handoff', 'SCN-worktree-purge-safety',
     'SCN-backlog-lifecycle', 'SCN-native-integration', 'SCN-resource-fifo',
     'SCN-fleet-fresh-resume', 'SCN-install-doctor-purge',
@@ -100,6 +101,60 @@ test('SCN-cli-domain-review: a generated proposal must be approved before instal
   assert.equal(existsSync(join(root, '.torch', 'domain-proposal.approved.json')), true);
 });
 
+test('SCN-cli-lifecycle-surface: runtime selection, selective startup, capture, brief, list, and detach are public', () => {
+  const root = repo();
+  const proposalPath = join(root, 'fleet-proposal.json');
+  assert.equal(run(root, ['domains', '--output', proposalPath, '--json']).status, 0);
+  const proposal = JSON.parse(readFileSync(proposalPath, 'utf8'));
+  proposal.review = {
+    status: 'approved', reviewedAt: '2026-09-27T00:00:00Z', reviewedBy: 'fixture-owner', notes: [],
+  };
+  writeFileSync(proposalPath, `${JSON.stringify(proposal, null, 2)}\n`);
+  const preview = run(root, [
+    'install', '--proposal', proposalPath, '--runtime', 'claude', '--dry-run', '--json',
+  ]);
+  assert.equal(preview.status, 0, preview.stderr || preview.stdout);
+  assert.deepEqual(JSON.parse(preview.stdout).runtimes, ['claude']);
+  const installed = run(root, [
+    'install', '--proposal', proposalPath, '--runtime', 'claude', '--yes', '--json',
+  ]);
+  assert.equal(installed.status, 0, installed.stderr || installed.stdout);
+  const config = JSON.parse(readFileSync(join(root, '.torch', 'torch.yaml'), 'utf8'));
+  assert.deepEqual(Object.keys(config.runtimes).sort(), ['claude', 'default']);
+  execFileSync('git', ['-C', root, 'add', '.torch', 'fleet-proposal.json']);
+  execFileSync('git', ['-C', root, 'commit', '-m', 'install torch']);
+  const worktreeParent = join(tmpdir(), `${basename(root)}-cli-worktrees`);
+  const worktrees = run(root, ['worktrees', '--parent', worktreeParent, '--yes', '--json']);
+  assert.equal(worktrees.status, 0, worktrees.stderr || worktrees.stdout);
+  const worker = proposal.domains[0].id;
+
+  const listed = run(root, ['list', '--json']);
+  assert.equal(listed.status, 0, listed.stderr || listed.stdout);
+  assert.equal(JSON.parse(listed.stdout).agents.some((agent) => agent.areaId === worker), true);
+  const brief = run(root, ['brief', '--area', worker, '--json']);
+  assert.equal(brief.status, 0, brief.stderr || brief.stdout);
+  assert.equal(JSON.parse(brief.stdout).areas[0].areaId, worker);
+  assert.match(JSON.parse(brief.stdout).areas[0].prompt, /Common fleet rules/);
+  const selective = run(root, ['up', '--only', worker, '--dry-run', '--json']);
+  assert.equal(selective.status, 0, selective.stderr || selective.stdout);
+  assert.deepEqual(JSON.parse(selective.stdout).actions.map((action) => action.areaId), [worker]);
+  const unknown = run(root, ['up', '--only', 'not-a-domain', '--dry-run', '--json']);
+  assert.equal(unknown.status, 1);
+  assert.equal(JSON.parse(unknown.stdout).blockers[0].code, 'FLEET_IDENTITY_MISSING');
+  const captured = run(root, ['capture', '--json']);
+  assert.equal(captured.status, 0, captured.stderr || captured.stdout);
+  assert.equal(existsSync(JSON.parse(captured.stdout).snapshotPath), true);
+  assert.equal(JSON.parse(run(root, ['detach', '--json']).stdout).error, 'APPROVAL_REQUIRED');
+  const detached = run(root, ['detach', '--yes', '--json']);
+  assert.equal(detached.status, 0, detached.stderr || detached.stdout);
+  assert.deepEqual(JSON.parse(detached.stdout).preserved, [
+    'tracked organization', 'worktrees', 'branches', 'local state',
+  ]);
+  const doctor = run(root, ['doctor', '--json']);
+  assert.equal(doctor.status, 0, doctor.stderr || doctor.stdout);
+  assert.equal(JSON.parse(doctor.stdout).findings.some((finding) => finding.code === 'FLEET_DETACHED'), true);
+});
+
 test('SCN-cli-control-plane: CLI messages, acknowledgements, ownership, and status share durable state', () => {
   const root = repo();
   const proposalPath = join(root, 'fleet-proposal.json');
diff --git a/test/fleet/kernel-lifecycle.test.mjs b/test/fleet/kernel-lifecycle.test.mjs
index bab4de5..ae53844 100644
--- a/test/fleet/kernel-lifecycle.test.mjs
+++ b/test/fleet/kernel-lifecycle.test.mjs
@@ -109,6 +109,28 @@ test('SCN-domain-approval: installation rejects stale or unapproved organization
   assert.equal(existsSync(join(root, '.torch')), false);
 });
 
+test('SCN-install-runtime-selection: approved runtime choices are explicit and cover every identity', () => {
+  const { root, env } = fixture();
+  const repository = inspectRepository(root);
+  const proposal = approvedProposal(repository);
+  assert.deepEqual(planInstall({ repository, proposal, env, runtimes: ['claude'] }).runtimes, ['claude']);
+  proposal.domains[0].runtime = 'codex';
+  assert.throws(
+    () => planInstall({ repository, proposal, env, runtimes: ['claude'] }),
+    (error) => error.code === 'INSTALL_RUNTIME_MISSING' && error.details.missing.includes('codex'),
+  );
+  assert.throws(
+    () => planInstall({ repository, proposal, env, runtimes: ['unknown'] }),
+    (error) => error.code === 'INSTALL_RUNTIME_INVALID',
+  );
+  const installed = installProject({
+    repository, proposal, env, projectId: 'runtime-selection', runtimes: ['claude', 'codex'],
+  });
+  assert.equal(installed.mutationPerformed, true);
+  const config = JSON.parse(readFileSync(join(root, '.torch', 'torch.yaml'), 'utf8'));
+  assert.deepEqual(Object.keys(config.runtimes).sort(), ['claude', 'codex', 'default']);
+});
+
 test('SCN-config-schema: installed configuration is strict, versioned, and migration-aware', () => {
   const { root, env } = fixture();
   const repository = inspectRepository(root);
diff --git a/test/fleet/lifecycle.test.mjs b/test/fleet/lifecycle.test.mjs
index 125db6d..b773cc1 100644
--- a/test/fleet/lifecycle.test.mjs
+++ b/test/fleet/lifecycle.test.mjs
@@ -12,7 +12,9 @@ import { proposeDomains } from '../../src/kernel/domains.mjs';
 import { inspectRepository } from '../../src/kernel/git.mjs';
 import { installProject } from '../../src/kernel/install.mjs';
 import { createWorktrees } from '../../src/kernel/worktrees.mjs';
-import { planFleetDown, planFleetUp, startFleet, stopFleet } from '../../src/runtime/lifecycle.mjs';
+import {
+  detachFleet, planFleetDetach, planFleetDown, planFleetUp, startFleet, stopFleet,
+} from '../../src/runtime/lifecycle.mjs';
 
 function fleetFixture({ workerRuntime = 'claude' } = {}) {
   const root = mkdtempSync(join(tmpdir(), 'torch-lifecycle-'));
@@ -70,12 +72,25 @@ test('SCN-fleet-fresh-resume: workers start before manager and stable identities
   assert.equal(stoppedIds.length, fresh.actions.length);
   assert.equal(existsSync(down.snapshotPath), true);
 
+  const detached = detachFleet({
+    plan: planFleetDetach({ repositoryRoot: fixture.root, controlPlane: control }),
+    controlPlane: control, stopRuntime: () => ({ stopped: true }),
+    now: () => new Date('2026-09-27T13:00:00Z'),
+  });
+  assert.equal(detached.detachedAt, '2026-09-27T13:00:00.000Z');
+  const metadataPath = join(planFleetDown({
+    repositoryRoot: fixture.root, controlPlane: control,
+  }).stateRoot, 'project.json');
+  assert.equal(JSON.parse(readFileSync(metadataPath, 'utf8')).detachedAt, detached.detachedAt);
+
   const resumed = planFleetUp({ repositoryRoot: fixture.root, controlPlane: control, adapter, fresh: false });
   assert.equal(resumed.actions.every((action) => action.mode === 'resume'), true);
   assert.deepEqual(
     resumed.actions.map((action) => action.runtimeSessionId),
     fresh.actions.map((action) => action.runtimeSessionId),
   );
+  startFleet({ plan: resumed, controlPlane: control, executor: () => ({ status: 0 }) });
+  assert.equal(JSON.parse(readFileSync(metadataPath, 'utf8')).detachedAt, null);
   control.close();
 });