diff --git a/packages/mosaic/src/commands/launch.ts b/packages/mosaic/src/commands/launch.ts
index 6f4e5041..3a0dd998 100644
--- a/packages/mosaic/src/commands/launch.ts
+++ b/packages/mosaic/src/commands/launch.ts
@@ -28,6 +28,7 @@ import { readRegularFileSecure } from '../fleet/secure-file.js';
 import { readPersonaContractBlock } from '../fleet/persona-contract.js';
 import { canonicalizeRoleClass } from './fleet-personas.js';
 import { launchClaudex, type ClaudexHarnessAdapter } from './claudex.js';
+import { runLeaseEnforcementDoctorCheck } from './lease-doctor-check.js';
 
 const MOSAIC_HOME = process.env['MOSAIC_HOME'] ?? join(homedir(), '.config', 'mosaic');
 const MAX_INSTALLED_TOOLS_BYTES = 256 * 1024;
@@ -1237,7 +1238,6 @@ export function registerLaunchCommands(program: Command): void {
   // Direct framework script delegates
   const directCommands: Record<string, { desc: string; script: string }> = {
     init: { desc: 'Generate SOUL.md (agent identity contract)', script: 'mosaic-init' },
-    doctor: { desc: 'Health audit — detect drift and missing files', script: 'mosaic-doctor' },
     sync: { desc: 'Sync skills from canonical source', script: 'mosaic-sync-skills' },
     bootstrap: {
       desc: 'Bootstrap a repo with Mosaic standards',
@@ -1256,4 +1256,67 @@ export function registerLaunchCommands(program: Command): void {
         delegateToScript(fwScript(script), cmd.args);
       });
   }
+
+  // `doctor` — the framework drift audit (bash script) PLUS the #869
+  // Point-1 C5 lease-enforcement activation check (TS, reusing C1's
+  // `leaseEnforcementActivatable()` and C3's `checkBrokerSupervisorHealth()`).
+  // Kept out of the generic `directCommands` loop above because this check
+  // must run and report BEFORE the bash script's own exit, and must be able
+  // to force a non-zero exit on its own — a silent pass on "enforcement
+  // hooks wired but activation absent" would leave a bricked host
+  // undiagnosed (see lease-doctor-check.ts docstring).
+  program
+    .command('doctor')
+    .description('Health audit — detect drift, missing files, and #869 lease-activation gaps')
+    .allowUnknownOption(true)
+    .allowExcessArguments(true)
+    .action(async (_opts: unknown, cmd: Command) => {
+      checkMosaicHome();
+      const leaseCheck = await runLeaseEnforcementDoctorCheck();
+      const leaseCheckFailed = printLeaseDoctorCheck(leaseCheck);
+      runDoctorScriptAndExit(fwScript('mosaic-doctor'), cmd.args, leaseCheckFailed);
+    });
+}
+
+/**
+ * Print the #869 C5 lease-enforcement doctor result using the same
+ * `[mosaic-doctor]` prefix the bash audit script uses, but with a distinct
+ * `[ERROR]` severity token (louder than the script's own `[WARN]`) — this is
+ * a hard, actionable brick warning, not a soft drift warning, and must never
+ * read as just one more line among the script's routine warnings. Silent on
+ * an `ok` result, matching this file's other pre-flight checks
+ * (`checkMosaicHome`, `checkFile`, `checkRuntime`) which only print on
+ * failure. Returns whether the check failed, so the caller can force a
+ * non-zero exit regardless of the bash script's own exit code.
+ */
+function printLeaseDoctorCheck(
+  result: Awaited<ReturnType<typeof runLeaseEnforcementDoctorCheck>>,
+): boolean {
+  if (result.status === 'error') {
+    console.error(`[mosaic-doctor] [ERROR] ${result.message}`);
+    return true;
+  }
+  return false;
+}
+
+/**
+ * Run the bash `mosaic-doctor` audit script (inheriting stdio, same as
+ * {@link delegateToScript}) and exit with a non-zero code if EITHER the
+ * script itself reported failure OR the lease-enforcement check above did —
+ * so `--fail-on-warn` and other script-level exit semantics are preserved,
+ * but the lease-enforcement ERROR can never be masked by an otherwise-green
+ * script run.
+ */
+function runDoctorScriptAndExit(scriptPath: string, args: string[], forceFailure: boolean): never {
+  if (!existsSync(scriptPath)) {
+    console.error(`[mosaic] Script not found: ${scriptPath}`);
+    process.exit(1);
+  }
+  let scriptExitCode = 0;
+  try {
+    execFileSync('bash', [scriptPath, ...args], { stdio: 'inherit', env: process.env });
+  } catch (err) {
+    scriptExitCode = (err as { status?: number }).status ?? 1;
+  }
+  process.exit(forceFailure ? 1 : scriptExitCode);
 }
diff --git a/packages/mosaic/src/commands/lease-doctor-check.spec.ts b/packages/mosaic/src/commands/lease-doctor-check.spec.ts
new file mode 100644
index 00000000..31a194c7
--- /dev/null
+++ b/packages/mosaic/src/commands/lease-doctor-check.spec.ts
@@ -0,0 +1,196 @@
+import { describe, expect, it } from 'vitest';
+import {
+  detectEnforcementHooksWired,
+  runLeaseEnforcementDoctorCheck,
+} from './lease-doctor-check.js';
+
+/**
+ * Red-first tests for issue #869 Point-1 C5 — the `mosaic doctor`
+ * lease-enforcement surfacing check.
+ *
+ * Root cause under test: enforcement hooks (`mutator-gate.py`,
+ * `receipt-observer-client.py`) can be wired into `~/.claude/settings.json`
+ * on a host where C1's `leaseEnforcementActivatable()` is false and/or C3's
+ * `checkBrokerSupervisorHealth()` reports unhealthy. That combination fails
+ * closed correctly, but must be surfaced LOUDLY by `mosaic doctor` rather
+ * than silently passing — this test suite exercises the three primary
+ * branches (wired+not-activatable, wired+healthy, not-wired) plus the
+ * broker-unhealthy variant.
+ *
+ * Every dependency is injected — no real `~/.claude/settings.json` and no
+ * real broker are ever touched.
+ */
+
+const WIRED_SETTINGS_JSON = JSON.stringify({
+  hooks: {
+    PreToolUse: [
+      {
+        matcher: '.*',
+        hooks: [
+          {
+            type: 'command',
+            command: 'python3 ~/.config/mosaic/tools/lease-broker/mutator-gate.py --runtime claude',
+          },
+        ],
+      },
+    ],
+    Stop: [
+      {
+        hooks: [
+          {
+            type: 'command',
+            command:
+              'python3 ~/.config/mosaic/tools/lease-broker/receipt-observer-client.py --runtime claude --latest-entry',
+          },
+        ],
+      },
+    ],
+  },
+});
+
+const UNWIRED_SETTINGS_JSON = JSON.stringify({
+  hooks: {
+    PostToolUse: [
+      {
+        matcher: 'Edit|MultiEdit|Write',
+        hooks: [{ type: 'command', command: '~/.config/mosaic/tools/qa/qa-hook-stdin.sh' }],
+      },
+    ],
+  },
+});
+
+describe('detectEnforcementHooksWired', () => {
+  it('detects the mutator-gate + receipt-observer markers when wired', () => {
+    const result = detectEnforcementHooksWired(JSON.parse(WIRED_SETTINGS_JSON));
+    expect(result.wired).toBe(true);
+    expect(result.matchedMarkers).toEqual(
+      expect.arrayContaining(['mutator-gate.py', 'receipt-observer-client.py']),
+    );
+  });
+
+  it('reports not wired when no enforcement markers are present', () => {
+    const result = detectEnforcementHooksWired(JSON.parse(UNWIRED_SETTINGS_JSON));
+    expect(result.wired).toBe(false);
+    expect(result.matchedMarkers).toEqual([]);
+  });
+
+  it('reports not wired for an empty settings object', () => {
+    expect(detectEnforcementHooksWired({}).wired).toBe(false);
+  });
+
+  it('detects wiring from just ONE marker (partial wiring is still dangerous)', () => {
+    const onlyMutatorGate = JSON.stringify({
+      hooks: {
+        PreToolUse: [
+          {
+            hooks: [{ type: 'command', command: 'python3 .../mutator-gate.py --runtime claude' }],
+          },
+        ],
+      },
+    });
+    const result = detectEnforcementHooksWired(JSON.parse(onlyMutatorGate));
+    expect(result.wired).toBe(true);
+    expect(result.matchedMarkers).toEqual(['mutator-gate.py']);
+  });
+});
+
+describe('runLeaseEnforcementDoctorCheck', () => {
+  it('RED: wired + not-activatable ⇒ LOUD error (not a silent pass)', async () => {
+    const result = await runLeaseEnforcementDoctorCheck({
+      readSettingsRaw: () => WIRED_SETTINGS_JSON,
+      isActivatable: () => false,
+      isBrokerHealthy: async () => true,
+    });
+
+    expect(result.status).toBe('error');
+    expect(result.wired).toBe(true);
+    expect(result.activatable).toBe(false);
+    expect(result.message).toMatch(/activation absent/);
+    expect(result.message).toMatch(/#869/);
+    expect(result.message.toLowerCase()).toMatch(/brick/);
+  });
+
+  it('wired + activatable + broker-unhealthy ⇒ LOUD error', async () => {
+    const result = await runLeaseEnforcementDoctorCheck({
+      readSettingsRaw: () => WIRED_SETTINGS_JSON,
+      isActivatable: () => true,
+      isBrokerHealthy: async () => false,
+    });
+
+    expect(result.status).toBe('error');
+    expect(result.wired).toBe(true);
+    expect(result.brokerHealthy).toBe(false);
+    expect(result.message).toMatch(/broker not healthy/);
+  });
+
+  it('wired + not-activatable + broker-unhealthy ⇒ LOUD error citing both reasons', async () => {
+    const result = await runLeaseEnforcementDoctorCheck({
+      readSettingsRaw: () => WIRED_SETTINGS_JSON,
+      isActivatable: () => false,
+      isBrokerHealthy: async () => false,
+    });
+
+    expect(result.status).toBe('error');
+    expect(result.message).toMatch(/activation absent/);
+    expect(result.message).toMatch(/broker not healthy/);
+  });
+
+  it('GREEN: wired + activatable + broker-healthy ⇒ ok', async () => {
+    const result = await runLeaseEnforcementDoctorCheck({
+      readSettingsRaw: () => WIRED_SETTINGS_JSON,
+      isActivatable: () => true,
+      isBrokerHealthy: async () => true,
+    });
+
+    expect(result.status).toBe('ok');
+    expect(result.wired).toBe(true);
+    expect(result.activatable).toBe(true);
+    expect(result.brokerHealthy).toBe(true);
+  });
+
+  it('GREEN: not-wired ⇒ ok, no false alarm (activation/broker never probed)', async () => {
+    let activatableCalled = false;
+    let brokerCalled = false;
+
+    const result = await runLeaseEnforcementDoctorCheck({
+      readSettingsRaw: () => UNWIRED_SETTINGS_JSON,
+      isActivatable: () => {
+        activatableCalled = true;
+        return false;
+      },
+      isBrokerHealthy: async () => {
+        brokerCalled = true;
+        return false;
+      },
+    });
+
+    expect(result.status).toBe('ok');
+    expect(result.wired).toBe(false);
+    expect(result.activatable).toBeNull();
+    expect(result.brokerHealthy).toBeNull();
+    // Not wired must short-circuit — never even consult activation/broker.
+    expect(activatableCalled).toBe(false);
+    expect(brokerCalled).toBe(false);
+  });
+
+  it('GREEN: settings.json absent ⇒ ok (never touches a real file — readSettingsRaw is injected)', async () => {
+    const result = await runLeaseEnforcementDoctorCheck({
+      readSettingsRaw: () => null,
+      isActivatable: () => false,
+      isBrokerHealthy: async () => false,
+    });
+
+    expect(result.status).toBe('ok');
+    expect(result.wired).toBe(false);
+  });
+
+  it('GREEN: malformed settings.json ⇒ ok (parse errors are not this card’s failure class)', async () => {
+    const result = await runLeaseEnforcementDoctorCheck({
+      readSettingsRaw: () => '{ not valid json',
+      isActivatable: () => false,
+      isBrokerHealthy: async () => false,
+    });
+
+    expect(result.status).toBe('ok');
+  });
+});
diff --git a/packages/mosaic/src/commands/lease-doctor-check.ts b/packages/mosaic/src/commands/lease-doctor-check.ts
new file mode 100644
index 00000000..866d7986
--- /dev/null
+++ b/packages/mosaic/src/commands/lease-doctor-check.ts
@@ -0,0 +1,210 @@
+/**
+ * Lease-enforcement doctor check (issue #869, Point-1 card C5).
+ *
+ * Root cause this guards against (#828 version skew, the same one C1/C3
+ * exist for): the Claude Code enforcement hooks (`mutator-gate.py` gating
+ * PreToolUse, `receipt-observer-client.py` observing Stop) can be WIRED into
+ * `~/.claude/settings.json` on a host where the ACTIVATION half is absent —
+ * no compatible CLI build (C1's `leaseEnforcementActivatable()`), or no
+ * healthy broker supervisor (C3's `checkBrokerSupervisorHealth()`). That
+ * combination is a silent brick: every gated tool call denies with
+ * GATE_UNAVAILABLE, and the fail-closed behavior is *correct* — but nothing
+ * surfaces it to an operator running `mosaic doctor` on an already-bricked
+ * host.
+ *
+ * This module answers one question — "if I ran right now, would I be
+ * bricked?" — by combining:
+ *
+ *   1. wiring detection: does `~/.claude/settings.json` reference either
+ *      enforcement-hook marker (`mutator-gate.py` / `receipt-observer-client.py`)?
+ *   2. C1's `leaseEnforcementActivatable()` — could activation satisfy
+ *      enforcement if it were exercised right now?
+ *   3. C3's `checkBrokerSupervisorHealth()` — is the broker supervisor
+ *      actually healthy?
+ *
+ * Not wired ⇒ ok (nothing to activate, no false alarm). Wired AND activatable
+ * AND broker-healthy ⇒ ok. Wired AND (NOT activatable OR broker unhealthy) ⇒
+ * a LOUD, actionable error — this module never silently passes that state.
+ *
+ * Every dependency (settings read, activation probe, broker-health check) is
+ * injectable so tests can drive every branch without ever touching a real
+ * `~/.claude/settings.json` or a real broker.
+ */
+
+import { readFileSync } from 'node:fs';
+import { homedir } from 'node:os';
+import { join } from 'node:path';
+import { leaseEnforcementActivatable, type ActivationProbeDeps } from './lease-activation-probe.js';
+import {
+  checkBrokerSupervisorHealth,
+  resolveBrokerSupervisorPaths,
+} from '../lease-broker/broker-supervisor.js';
+import { DEFAULT_MOSAIC_HOME } from '../constants.js';
+
+/** Markers identifying the two enforcement-hook halves wired via the
+ * framework reseed. Either marker's presence in `settings.json` means
+ * enforcement is wired — a host can be bricked with just one half present. */
+const ENFORCEMENT_HOOK_MARKERS = ['mutator-gate.py', 'receipt-observer-client.py'] as const;
+
+export interface EnforcementHooksWiredResult {
+  readonly wired: boolean;
+  readonly matchedMarkers: readonly string[];
+}
+
+/**
+ * Detect whether the Claude Code enforcement hooks (mutator-gate /
+ * receipt-observer) are wired into an already-parsed `settings.json`.
+ * Pure/testable — takes parsed JSON, never touches the filesystem itself.
+ */
+export function detectEnforcementHooksWired(settings: unknown): EnforcementHooksWiredResult {
+  const serialized = JSON.stringify(settings ?? {});
+  const matchedMarkers = ENFORCEMENT_HOOK_MARKERS.filter((marker) => serialized.includes(marker));
+  return { wired: matchedMarkers.length > 0, matchedMarkers };
+}
+
+export interface LeaseDoctorCheckDeps {
+  /**
+   * Read raw `settings.json` text; return `null` if the file is absent.
+   * Defaults to reading the real `~/.claude/settings.json`. ALWAYS inject a
+   * fake in tests — never point this at a real host's settings file.
+   */
+  readSettingsRaw?: () => string | null;
+  /** Defaults to {@link leaseEnforcementActivatable} (C1). Inject for tests. */
+  isActivatable?: (deps?: ActivationProbeDeps) => boolean;
+  /**
+   * Defaults to a real broker-supervisor health check (C3) rooted at
+   * `mosaicHome`. Inject for tests — never point this at a real broker.
+   */
+  isBrokerHealthy?: () => Promise<boolean>;
+  /** Mosaic home used to resolve default broker-supervisor paths. Defaults to
+   * `$MOSAIC_HOME` or `~/.config/mosaic`. */
+  mosaicHome?: string;
+}
+
+export type LeaseDoctorCheckStatus = 'ok' | 'error';
+
+export interface LeaseDoctorCheckResult {
+  readonly status: LeaseDoctorCheckStatus;
+  readonly wired: boolean;
+  /** `null` when hooks are not wired (activation/broker were never probed). */
+  readonly activatable: boolean | null;
+  /** `null` when hooks are not wired (activation/broker were never probed). */
+  readonly brokerHealthy: boolean | null;
+  readonly message: string;
+}
+
+function defaultReadSettingsRaw(): string | null {
+  const settingsPath = join(homedir(), '.claude', 'settings.json');
+  try {
+    return readFileSync(settingsPath, 'utf8');
+  } catch (error) {
+    if (isEnoent(error)) return null;
+    throw error;
+  }
+}
+
+function isEnoent(error: unknown): boolean {
+  return (
+    typeof error === 'object' &&
+    error !== null &&
+    'code' in error &&
+    (error as NodeJS.ErrnoException).code === 'ENOENT'
+  );
+}
+
+function defaultMosaicHome(): string {
+  return process.env['MOSAIC_HOME'] ?? DEFAULT_MOSAIC_HOME;
+}
+
+async function defaultIsBrokerHealthy(mosaicHome: string): Promise<boolean> {
+  // `frameworkRoot` only feeds SOURCE paths (unit/wrapper/daemon file
+  // locations for `applyBrokerSupervisor`); the health check only reads
+  // TARGET paths (`unitTargetPath`, `socketPath`), both derived from
+  // `mosaicHome`/`homeDir`/`env` alone. Passing `mosaicHome` again here is
+  // therefore safe and never resolves or touches a framework checkout.
+  const paths = resolveBrokerSupervisorPaths({ mosaicHome, frameworkRoot: mosaicHome });
+  return (await checkBrokerSupervisorHealth(paths)).healthy;
+}
+
+/**
+ * Surface the #869 fail-closed brick scenario as a LOUD `mosaic doctor`
+ * error. See module docstring for the full decision table.
+ */
+export async function runLeaseEnforcementDoctorCheck(
+  deps: LeaseDoctorCheckDeps = {},
+): Promise<LeaseDoctorCheckResult> {
+  const readSettingsRaw = deps.readSettingsRaw ?? defaultReadSettingsRaw;
+  const mosaicHome = deps.mosaicHome ?? defaultMosaicHome();
+  const isActivatable = deps.isActivatable ?? leaseEnforcementActivatable;
+  const isBrokerHealthy = deps.isBrokerHealthy ?? (() => defaultIsBrokerHealthy(mosaicHome));
+
+  const raw = readSettingsRaw();
+  if (raw === null) {
+    return {
+      status: 'ok',
+      wired: false,
+      activatable: null,
+      brokerHealthy: null,
+      message: 'Claude Code settings.json not found — lease-enforcement hooks not wired.',
+    };
+  }
+
+  let parsed: unknown;
+  try {
+    parsed = JSON.parse(raw);
+  } catch {
+    // Malformed settings.json is a different failure class than this card
+    // owns (C2 guards install-time writes); report ok rather than
+    // misattributing a parse error to the #869 activation gap.
+    return {
+      status: 'ok',
+      wired: false,
+      activatable: null,
+      brokerHealthy: null,
+      message:
+        'Claude Code settings.json could not be parsed — skipping lease-enforcement wiring check.',
+    };
+  }
+
+  const { wired, matchedMarkers } = detectEnforcementHooksWired(parsed);
+  if (!wired) {
+    return {
+      status: 'ok',
+      wired: false,
+      activatable: null,
+      brokerHealthy: null,
+      message:
+        'Lease-enforcement hooks not wired in ~/.claude/settings.json — nothing to activate.',
+    };
+  }
+
+  const activatable = isActivatable();
+  const brokerHealthy = await isBrokerHealthy();
+
+  if (activatable && brokerHealthy) {
+    return {
+      status: 'ok',
+      wired: true,
+      activatable,
+      brokerHealthy,
+      message: `Lease-enforcement hooks wired (${matchedMarkers.join(', ')}) — activation capability present and broker healthy.`,
+    };
+  }
+
+  const reasons: string[] = [];
+  if (!activatable) reasons.push('activation absent (leaseEnforcementActivatable() is false)');
+  if (!brokerHealthy) {
+    reasons.push('broker not healthy (checkBrokerSupervisorHealth() reports unhealthy)');
+  }
+
+  return {
+    status: 'error',
+    wired: true,
+    activatable,
+    brokerHealthy,
+    message:
+      `Lease-enforcement hooks (${matchedMarkers.join(', ')}) are wired in ~/.claude/settings.json, but ${reasons.join(' and ')}. ` +
+      'Every gated tool call will fail closed and BRICK this agent (see #869). ' +
+      'Remediate by activating the lease-broker supervisor (systemd unit + socket) or by removing the enforcement hooks from ~/.claude/settings.json.',
+  };
+}