feat(mosaic): mosaic update re-seeds framework + relaunches agents (#609)

Closes R13 (F3-m3). mosaic update installed the new npm CLI but never
re-seeded ~/.config/mosaic from the package's bundled framework/, so shipped
launcher/runtime changes (agent-name export + native HB) stayed DORMANT until
a manual re-seed — operators got the new CLI on a stale framework.

- update-checker.ts: resolveBundledFrameworkRoot, buildReseedCommand (install.sh
  in MOSAIC_SYNC_ONLY=1 MOSAIC_INSTALL_MODE=keep — the P4 data-safe reconcile:
  framework-owned overwrite + backup-once; SOUL/USER/*.local/credentials kept),
  runFrameworkReseed, readRosterAgentNames, buildRelaunchCommands.
- cli.ts update: after a successful CLI install that includes @mosaicstack/mosaic,
  re-seed the framework (default-on; --no-reseed to skip). Then --relaunch restarts
  rostered agents (systemctl --user restart mosaic-agent@<name>), else prints clear
  activation guidance. Only re-seeds when the framework-bearing package updated.

Flow: update CLI -> re-seed framework (data-safe) -> relaunch agents (opt-in).

Verified: 6 new unit tests + 19 runtime + 26 launch tests green; tsc/eslint/
prettier clean. Sync data-safety already proven (P4 matrix + live validation).

Refs #609

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EsgTQzV5YUGk1JtCLP4B83

docs/TASKS.md

@@ -58,11 +58,3 @@ Active workstream is **W1 — Federation v1**. Workers should:
 ## F3-m3 — mosaic update re-seeds framework + relaunches agents (#609) — feat/f3-m3-update-reseed
 
 - Status: implemented + tested. Closes R13: `mosaic update` now re-seeds the framework (data-safe MOSAIC_SYNC_ONLY) after the CLI install so shipped launcher/runtime changes activate; `--relaunch` restarts rostered agents; `--no-reseed` opts out. Detail: scratchpads/f3-m3-update-reseed.md.
-
-## Fleet-polish bundle — boot-survival symmetry (#611) — feat/fleet-polish-bundle
-
-- Status: implemented + tested. disable-on-remove (boot-resurrection bug, TDD) + add-enable + init-R5 hard guarantee. 4 new + 147 existing fleet tests green. Detail: scratchpads/fleet-polish-bundle.md.
-
-## Fleet enhancer role + two-agent floor (#614) — feat/fleet-enhancer-floor (stacked on #612)
-
-- Status: implemented + tested. enhancer added to 4 presets; init guarantees 1 orchestrator + >=1 enhancer; remove protects the sole enhancer; enhancer role doc. 155 fleet tests green. Detail: scratchpads/fleet-enhancer-floor.md.

docs/scratchpads/fleet-enhancer-floor.md

@@ -1,26 +0,0 @@
-# Fleet enhancer role + two-agent floor (#614)
-
-- **Issue:** #614 · **Branch:** `feat/fleet-enhancer-floor` (stacked on #612 `feat/fleet-polish-bundle`)
-- **Doctrine:** `docs/fleet/north-star.md` (PR #613) — every fleet = orchestrator + enhancer minimum.
-
-## Changes
-
-- **Presets** (general, coding, research, hybrid): add `enhancer` (claude, `class: enhancer`,
-  `persistent_persona: true`) as a core always-on agent alongside the orchestrator. minimal/local-canary
-  unchanged.
-- **fleet.ts**: `countEnhancers` helper; init guarantee extended — non-minimal profiles must yield
-  exactly 1 orchestrator AND >=1 enhancer (hard-fail otherwise); `removeAgentFromRoster` refuses to drop
-  the sole enhancer (symmetric with the sole-orchestrator guard) so the floor holds at runtime, not just init.
-- **Role doc**: `framework/fleet/roles/enhancer.md` — the enhancer mandate (monitor → analyze → plan →
-  upgrade tools/skills/harness WITH orchestrator → file Mosaic Stack bug reports) + boundaries (does NOT
-  code or review).
-
-## Verification
-
-- 155 fleet tests green (new: countEnhancers; remove-sole-enhancer guard; remove-allows-when-another;
-  init two-agent-floor; every-non-minimal-preset-has-enhancer; updated preset rosters). tsc/eslint/
-  prettier/sanitize clean. TDD on the init guarantee + remove protection.
-
-## Stacking
-
-Built on #612's init-R5 code. PR shows #612 + enhancer until #612 merges; then rebase onto main → clean.

docs/scratchpads/fleet-polish-bundle.md

@@ -1,20 +0,0 @@
-# Fleet-polish bundle — boot-survival symmetry (#611)
-
-- **Issue:** #611 · **Branch:** `feat/fleet-polish-bundle` · From the Lead's Codex symmetry-gap finding.
-
-## Three fixes
-
-1. **disable-on-remove (BUG, TDD).** `fleet remove` stopped + deleted roster/env/heartbeat but never
-   `systemctl --user disable mosaic-agent@NAME.service` → a removed-but-enabled unit could resurrect on
-   reboot pointing at deleted config. Fix: `buildSystemdDisableCommand` + disable in `remove`
-   (best-effort, gated on !--keep-files).
-2. **add-enable.** `fleet add` now enables the new agent's unit for boot-survival (best-effort,
-   independent of --start) — symmetry with disable-on-remove.
-3. **init-R5 guarantee.** `fleet init --write` now FAILS HARD when a non-minimal profile doesn't yield
-   exactly one orchestrator (was a soft warning). `minimal` (sanctioned no-orchestrator) still allowed.
-
-## Verification
-
-- 4 new tests (disable builder; remove-invokes-disable; add-invokes-enable; init general → exactly 1
-  orchestrator) + 147 existing fleet tests green (151 total). tsc/eslint/prettier clean.
-- TDD on the disable bug per contract.

packages/mosaic/framework/fleet/examples/coding.yaml

@@ -15,10 +15,6 @@ agents:
     runtime: claude
     class: orchestrator
     persistent_persona: true
-  - name: enhancer
-    runtime: claude
-    class: enhancer
-    persistent_persona: true
   - name: coder0
     runtime: pi
     class: implementer

packages/mosaic/framework/fleet/examples/general.yaml

@@ -15,10 +15,6 @@ agents:
     runtime: claude
     class: orchestrator
     persistent_persona: true
-  - name: enhancer
-    runtime: claude
-    class: enhancer
-    persistent_persona: true
   - name: generalist
     runtime: pi
     class: worker

packages/mosaic/framework/fleet/examples/hybrid.yaml

@@ -15,10 +15,6 @@ agents:
     runtime: claude
     class: orchestrator
     persistent_persona: true
-  - name: enhancer
-    runtime: claude
-    class: enhancer
-    persistent_persona: true
   - name: coder0
     runtime: pi
     class: implementer

packages/mosaic/framework/fleet/examples/research.yaml

@@ -15,10 +15,6 @@ agents:
     runtime: claude
     class: orchestrator
     persistent_persona: true
-  - name: enhancer
-    runtime: claude
-    class: enhancer
-    persistent_persona: true
   - name: researcher0
     runtime: pi
     class: researcher

packages/mosaic/framework/fleet/roles/enhancer.md

@@ -1,41 +0,0 @@
-# Enhancer — fleet role definition
-
-The **enhancer** is one half of the fleet's two-agent floor: every fleet runs, at
-minimum, an **orchestrator** and an **enhancer**. The orchestrator drives delivery;
-the enhancer makes the fleet _get better at delivering_ over time.
-
-It is a **core, always-on** agent (`class: enhancer`, `persistent_persona: true`),
-not an ephemeral per-lane worker.
-
-## Mandate
-
-The enhancer runs the fleet's **continuous-improvement loop**:
-
-1. **Monitor** fleet activity — agents, heartbeats, sessions, throughput, failures.
-2. **Analyze** for enhancements and optimizations — friction, gaps, recurring defects,
-   missing or broken tools, skill/harness shortfalls.
-3. **Plan** a remediation: a concrete improvement with rationale and expected effect.
-4. **Upgrade fleet capability — with the orchestrator** — tool creation/repair, skills,
-   harness improvements. The orchestrator owns fleet composition; the enhancer advises and
-   implements improvements to the _means of production_, not the product.
-5. **File upstream bug reports** to Mosaic Stack for real defects, so they flow back to the
-   framework for proper remediation rather than being patched over locally.
-6. **Recommend which agents are needed** — advise the orchestrator on roles to add/remove as
-   the mission evolves.
-
-## Boundaries
-
-- **Does NOT write product/source code.**
-- **Does NOT review code** (that is the code-review / security-review roles).
-- **Does NOT perform delivery tasks.**
-
-Improvement and diagnosis only. When the enhancer finds work that requires coding or review,
-it files it (bug report / recommendation) and the orchestrator materializes the right worker.
-
-## Why two, not one
-
-The orchestrator alone optimizes for _this_ delivery; the enhancer optimizes for _every future_
-delivery — self-healing the fleet's tools, skills, and harnesses, and routing real defects
-upstream. Together they are the irreducible core; every other role is added on demand.
-
-> Doctrine: `docs/fleet/north-star.md` (two-agent floor + role library).

packages/mosaic/src/commands/fleet.spec.ts

@@ -14,13 +14,11 @@ import {
   buildEnableLingerCommand,
   buildFleetServiceCommand,
   buildSystemdEnableCommand,
-  buildSystemdDisableCommand,
   buildSystemdShowCommand,
   buildTmuxListPanesCommand,
   buildTmuxListSessionsCommand,
   classifySendResult,
   countOrchestrators,
-  countEnhancers,
   detectDrift,
   enableFleetUnits,
   FLEET_PROFILES,
@@ -985,129 +983,6 @@ describe('fleet ps — drift detection', () => {
   });
 });
 
-describe('fleet-polish bundle — boot-survival symmetry', () => {
-  async function rosterHome(agents: string): Promise<string> {
-    const home = await tempDir();
-    await mkdir(join(home, 'fleet'), { recursive: true });
-    await writeFile(join(home, 'fleet', 'roster.yaml'), agents);
-    return home;
-  }
-
-  it('buildSystemdDisableCommand returns the systemctl --user disable array', () => {
-    expect(buildSystemdDisableCommand('mosaic-agent@coder0.service')).toEqual([
-      'systemctl',
-      '--user',
-      'disable',
-      'mosaic-agent@coder0.service',
-    ]);
-  });
-
-  it('fleet remove DISABLES the unit so a removed agent cannot resurrect on boot', async () => {
-    const home = await rosterHome(
-      [
-        'version: 1',
-        'transport: tmux',
-        'agents:',
-        '  - name: orchestrator',
-        '    runtime: pi',
-        '    class: orchestrator',
-        '  - name: coder0',
-        '    runtime: codex',
-        '    class: worker',
-      ].join('\n') + '\n',
-    );
-    const calls: string[][] = [];
-    const runner: CommandRunner = async (command, args) => {
-      calls.push([command, ...args]);
-      return { stdout: '', stderr: '', exitCode: 0 };
-    };
-    const program = new Command();
-    program.exitOverride();
-    registerFleetCommand(program, { runner, mosaicHome: home });
-    try {
-      await program.parseAsync(['node', 'mosaic', 'fleet', 'remove', 'coder0']);
-      expect(calls).toContainEqual([
-        'systemctl',
-        '--user',
-        'disable',
-        'mosaic-agent@coder0.service',
-      ]);
-      // stop must still happen too
-      expect(calls).toContainEqual(['systemctl', '--user', 'stop', 'mosaic-agent@coder0.service']);
-    } finally {
-      await rm(home, { recursive: true, force: true });
-    }
-  });
-
-  it('fleet add ENABLES the new agent unit for boot-survival', async () => {
-    const home = await rosterHome(
-      ['version: 1', 'transport: tmux', 'agents:', '  - name: coder0', '    runtime: codex'].join(
-        '\n',
-      ) + '\n',
-    );
-    const calls: string[][] = [];
-    const runner: CommandRunner = async (command, args) => {
-      calls.push([command, ...args]);
-      return { stdout: '', stderr: '', exitCode: 0 };
-    };
-    const program = new Command();
-    program.exitOverride();
-    registerFleetCommand(program, { runner, mosaicHome: home });
-    try {
-      await program.parseAsync([
-        'node',
-        'mosaic',
-        'fleet',
-        'add',
-        'coder1',
-        '--runtime',
-        'codex',
-        '--class',
-        'worker',
-        '--no-start',
-      ]);
-      expect(calls).toContainEqual([
-        'systemctl',
-        '--user',
-        'enable',
-        'mosaic-agent@coder1.service',
-      ]);
-    } finally {
-      await rm(home, { recursive: true, force: true });
-    }
-  });
-
-  it('fleet init --write enforces the two-agent floor (1 orchestrator + >=1 enhancer)', async () => {
-    // The general profile must yield exactly one orchestrator AND at least one
-    // enhancer; the guarantee is enforced (not just warned). Happy path writes cleanly.
-    const home = await tempDir();
-    const program = new Command();
-    program.exitOverride();
-    registerFleetCommand(program, {
-      runner: async () => ({ stdout: '', stderr: '', exitCode: 0 }),
-      mosaicHome: home,
-    });
-    try {
-      await program.parseAsync([
-        'node',
-        'mosaic',
-        'fleet',
-        'init',
-        '--profile',
-        'general',
-        '--write',
-      ]);
-      const written = await readFile(join(home, 'fleet', 'roster.yaml'), 'utf8');
-      const orchestrators = (written.match(/class:\s*orchestrator/g) ?? []).length;
-      const enhancers = (written.match(/class:\s*enhancer/g) ?? []).length;
-      expect(orchestrators).toBe(1);
-      expect(enhancers).toBeGreaterThanOrEqual(1);
-    } finally {
-      await rm(home, { recursive: true, force: true });
-    }
-  });
-});
-
 describe('fleet install — auto-enable units for boot-survival', () => {
   it('buildSystemdEnableCommand and buildEnableLingerCommand return correct command arrays', () => {
     expect(buildSystemdEnableCommand('mosaic-tmux-holder.service')).toEqual([
@@ -2313,63 +2188,47 @@ describe('fleet preset rosters', () => {
     },
   );
 
-  it('general preset: orchestrator + enhancer + one generalist worker', async () => {
+  it('general preset: orchestrator + one generalist worker', async () => {
     const roster = await loadFleetRoster(join(examplesDir, 'general.yaml'));
-    expect(roster.agents.map((a) => a.name)).toEqual(['orchestrator', 'enhancer', 'generalist']);
+    expect(roster.agents.map((a) => a.name)).toEqual(['orchestrator', 'generalist']);
     expect(roster.agents.find((a) => a.name === 'orchestrator')?.runtime).toBe('claude');
-    expect(roster.agents.find((a) => a.name === 'enhancer')?.className).toBe('enhancer');
     expect(roster.agents.find((a) => a.name === 'generalist')?.runtime).toBe('pi');
   });
 
-  it('coding preset: orchestrator + enhancer + coder0 + coder1 + reviewer', async () => {
+  it('coding preset: orchestrator + coder0 + coder1 + reviewer', async () => {
     const roster = await loadFleetRoster(join(examplesDir, 'coding.yaml'));
     expect(roster.agents.map((a) => a.name)).toEqual([
       'orchestrator',
-      'enhancer',
       'coder0',
       'coder1',
       'reviewer',
     ]);
   });
 
-  it('research preset: orchestrator + enhancer + researcher0 + researcher1 + analyst', async () => {
+  it('research preset: orchestrator + researcher0 + researcher1 + analyst', async () => {
     const roster = await loadFleetRoster(join(examplesDir, 'research.yaml'));
     expect(roster.agents.map((a) => a.name)).toEqual([
       'orchestrator',
-      'enhancer',
       'researcher0',
       'researcher1',
       'analyst',
     ]);
   });
 
-  it('hybrid preset: orchestrator + enhancer + coder0 + researcher0 + reviewer', async () => {
+  it('hybrid preset: orchestrator + coder0 + researcher0 + reviewer', async () => {
     const roster = await loadFleetRoster(join(examplesDir, 'hybrid.yaml'));
     expect(roster.agents.map((a) => a.name)).toEqual([
       'orchestrator',
-      'enhancer',
       'coder0',
       'researcher0',
       'reviewer',
     ]);
   });
 
-  it('every non-minimal preset carries an enhancer (two-agent floor)', async () => {
-    for (const preset of ['general', 'coding', 'research', 'hybrid'] as FleetProfile[]) {
-      const roster = await loadFleetRoster(join(examplesDir, `${preset}.yaml`));
-      expect(countOrchestrators(roster)).toBe(1);
-      expect(countEnhancers(roster)).toBeGreaterThanOrEqual(1);
-      expect(roster.agents.find((a) => a.className === 'enhancer')?.runtime).toBe('claude');
-    }
-  });
-
   it('worker agents in new presets use pi runtime with model_hint openai-codex/gpt-5.5:high', async () => {
     for (const preset of ['general', 'coding', 'research', 'hybrid'] as FleetProfile[]) {
       const roster = await loadFleetRoster(join(examplesDir, `${preset}.yaml`));
-      // Core agents (orchestrator + enhancer) run claude; only ephemeral workers are pi.
-      const workers = roster.agents.filter(
-        (a) => a.className !== 'orchestrator' && a.className !== 'enhancer',
-      );
+      const workers = roster.agents.filter((a) => a.name !== 'orchestrator');
       for (const worker of workers) {
         expect(worker.runtime).toBe('pi');
         expect(worker.modelHint).toBe('openai-codex/gpt-5.5:high');
@@ -2511,43 +2370,6 @@ describe('fleet add/remove — pure helpers', () => {
     expect(updated.agents.map((a) => a.name)).toEqual(['orchestrator2', 'coder0']);
   });
 
-  it('countEnhancers counts enhancer-class agents (two-agent floor)', () => {
-    const roster: FleetRoster = {
-      ...baseRoster,
-      agents: [
-        { name: 'orchestrator', runtime: 'claude', className: 'orchestrator' },
-        { name: 'enhancer', runtime: 'claude', className: 'enhancer' },
-        { name: 'coder0', runtime: 'codex', className: 'worker' },
-      ],
-    };
-    expect(countEnhancers(roster)).toBe(1);
-    expect(countEnhancers(baseRoster)).toBe(0);
-  });
-
-  it('removeAgentFromRoster throws when removing the sole enhancer (two-agent floor)', () => {
-    const roster: FleetRoster = {
-      ...baseRoster,
-      agents: [
-        { name: 'orchestrator', runtime: 'claude', className: 'orchestrator' },
-        { name: 'enhancer', runtime: 'claude', className: 'enhancer' },
-      ],
-    };
-    expect(() => removeAgentFromRoster(roster, 'enhancer')).toThrow('sole enhancer');
-  });
-
-  it('removeAgentFromRoster allows removing an enhancer when another remains', () => {
-    const roster: FleetRoster = {
-      ...baseRoster,
-      agents: [
-        { name: 'orchestrator', runtime: 'claude', className: 'orchestrator' },
-        { name: 'enhancer', runtime: 'claude', className: 'enhancer' },
-        { name: 'enhancer2', runtime: 'claude', className: 'enhancer' },
-      ],
-    };
-    const updated = removeAgentFromRoster(roster, 'enhancer');
-    expect(updated.agents.map((a) => a.name)).toEqual(['orchestrator', 'enhancer2']);
-  });
-
   it('serializeRosterToYaml produces YAML that round-trips through loadFleetRoster', async () => {
     const yaml = serializeRosterToYaml(baseRoster);
     expect(typeof yaml).toBe('string');

packages/mosaic/src/commands/fleet.ts

@@ -227,15 +227,6 @@ export function buildSystemdEnableCommand(unit: string): string[] {
   return ['systemctl', '--user', 'enable', unit];
 }
 
-/**
- * Returns the systemctl --user disable command for a given unit.
- * Used by `fleet remove` so a removed agent's enabled unit cannot resurrect on
- * boot pointing at deleted config (boot-survival symmetry with enable-on-add).
- */
-export function buildSystemdDisableCommand(unit: string): string[] {
-  return ['systemctl', '--user', 'disable', unit];
-}
-
 /**
  * Returns the loginctl enable-linger command for a given user.
  * Linger allows user systemd services to survive logout.
@@ -881,33 +872,20 @@ export function registerFleetCommand(program: Command, deps: FleetCommandDeps =
       await mkdir(dirname(destination), { recursive: true });
       await writeFile(destination, content);
 
-      // Guarantee the two-agent floor: exactly one orchestrator AND at least
-      // one enhancer for every profile except the sanctioned no-orchestrator
-      // `minimal` preset. A mismatch means a corrupted/edited preset — fail hard
-      // rather than write a malformed fleet.
+      // Validate: exactly one orchestrator required (R5) — friendly summary on success.
       const written = await loadFleetRoster(destination);
       const orchCount = countOrchestrators(written);
-      const enhancerCount = countEnhancers(written);
-      if (profile === 'minimal') {
+      if (orchCount !== 1) {
+        process.stderr.write(
+          `Warning: fleet roster at ${destination} has ${orchCount} orchestrator agent(s) (expected exactly 1).\n`,
+        );
         console.log(
-          `Initialized ${profile} fleet: ${written.agents.length} agent(s) (no orchestrator). Next: mosaic fleet install`,
-        );
-      } else if (orchCount !== 1) {
-        throw new Error(
-          `Fleet init failed: the "${profile}" roster has ${orchCount} orchestrator agent(s), ` +
-            `expected exactly 1 (R5). The preset may be corrupted — re-install the framework.`,
-        );
-      } else if (enhancerCount < 1) {
-        throw new Error(
-          `Fleet init failed: the "${profile}" roster has no enhancer agent. Every fleet keeps an ` +
-            `orchestrator + enhancer minimum (two-agent floor). The preset may be corrupted — ` +
-            `re-install the framework.`,
+          `Initialized ${profile} fleet: ${written.agents.length} agent(s). Next: mosaic fleet install`,
         );
       } else {
-        const workerCount = written.agents.length - 1 - enhancerCount;
+        const workerCount = written.agents.length - 1;
         console.log(
-          `Initialized ${profile} fleet: 1 orchestrator + ${enhancerCount} enhancer(s) + ` +
-            `${workerCount} worker(s). Next: mosaic fleet install`,
+          `Initialized ${profile} fleet: 1 orchestrator + ${workerCount} agent(s). Next: mosaic fleet install`,
         );
       }
     });
@@ -1240,24 +1218,6 @@ export function registerFleetCommand(program: Command, deps: FleetCommandDeps =
 
         console.log(`Added ${name} (${opts.runtime}/${opts.class}) to the fleet.`);
 
-        // Enable the unit for boot-survival (non-fatal) — symmetry with
-        // disable-on-remove. Independent of --start so a queued agent still
-        // survives a reboot once its unit exists.
-        try {
-          const enableResult = await runner(
-            ...splitCommand(buildSystemdEnableCommand(`mosaic-agent@${name}.service`)),
-          );
-          if (enableResult.exitCode !== 0) {
-            process.stderr.write(
-              `Warning: could not enable mosaic-agent@${name}.service: ${enableResult.stderr || enableResult.stdout || 'non-zero exit'}\n`,
-            );
-          }
-        } catch (err) {
-          process.stderr.write(
-            `Warning: enable command failed for ${name}: ${err instanceof Error ? err.message : String(err)}\n`,
-          );
-        }
-
         if (opts.start !== false) {
           await runChecked(runner, buildFleetServiceCommand('start', name));
           console.log(`Started mosaic-agent@${name}.service.`);
@@ -1294,26 +1254,6 @@ export function registerFleetCommand(program: Command, deps: FleetCommandDeps =
         );
       }
 
-      // Disable the unit (non-fatal) so an enabled instance cannot resurrect on
-      // boot pointing at the now-deleted config — boot-survival symmetry with
-      // enable-on-add. Skipped only when --keep-files keeps the config in place.
-      if (!opts.keepFiles) {
-        try {
-          const disableResult = await runner(
-            ...splitCommand(buildSystemdDisableCommand(`mosaic-agent@${name}.service`)),
-          );
-          if (disableResult.exitCode !== 0) {
-            process.stderr.write(
-              `Warning: could not disable mosaic-agent@${name}.service: ${disableResult.stderr || disableResult.stdout || 'non-zero exit'}\n`,
-            );
-          }
-        } catch (err) {
-          process.stderr.write(
-            `Warning: disable command failed for ${name}: ${err instanceof Error ? err.message : String(err)}\n`,
-          );
-        }
-      }
-
       // Write updated roster
       await writeFile(rosterPath, serializeRosterToYaml(updatedRoster));
 
@@ -1954,15 +1894,6 @@ export function countOrchestrators(roster: FleetRoster): number {
   return roster.agents.filter((a) => a.className === 'orchestrator').length;
 }
 
-/**
- * Count enhancer agents in a parsed roster. The two-agent floor (north-star)
- * requires every non-minimal fleet to carry at least one enhancer alongside the
- * sole orchestrator.
- */
-export function countEnhancers(roster: FleetRoster): number {
-  return roster.agents.filter((a) => a.className === 'enhancer').length;
-}
-
 /** Valid runtime identifiers for fleet agents. */
 export const VALID_FLEET_RUNTIMES: readonly string[] = [
   'pi',
@@ -2005,15 +1936,6 @@ export function removeAgentFromRoster(roster: FleetRoster, name: string): FleetR
       `Cannot remove agent "${name}": it is the sole orchestrator. Add another orchestrator first (R5).`,
     );
   }
-  // Two-agent floor: never drop the last enhancer (the continuous-improvement
-  // loop). Symmetric with the sole-orchestrator guard.
-  const remainingEnhancerCount = remaining.filter((a) => a.className === 'enhancer').length;
-  if (remainingEnhancerCount === 0 && agent.className === 'enhancer') {
-    throw new Error(
-      `Cannot remove agent "${name}": it is the sole enhancer. Every fleet keeps at least one ` +
-        `enhancer (two-agent floor). Add another enhancer first.`,
-    );
-  }
   return {
     ...roster,
     agents: remaining,