test(fleet): hermetic heartbeat tests — temp run-dir + no leaked sidecars

Tests 3, 4, 5 previously returned synthetic pane PIDs (99999/99998/99997)
from their fake list-panes shims but did not set MOSAIC_HEARTBEAT_RUN_DIR,
causing the launcher to fall back to the real ~/.config/mosaic/fleet/run
and potentially spawn a background sidecar against an arbitrary host PID.

Fix:
- list-panes in tests 3/4/5 now returns empty string → PANE_PID stays
  unset → no sidecar is spawned for tests where heartbeat is not under test.
- MOSAIC_HEARTBEAT_RUN_DIR is exported to a per-test mktemp dir in each
  fake-tmux test (3, 4, 5) as defence-in-depth so even if the sidecar
  code path changes, it can never write to the real fleet run dir.
- New temp dirs are registered in CLEANUP_DIRS so they are removed by the
  existing EXIT trap.
- Tests 6 and 7 (the dedicated heartbeat tests) are unchanged: test 6 uses
  a real tmux pane PID + its own HB_RUN_DIR, test 7 intercepts via a fake
  setsid shim that captures args and exits immediately.
- All 7 tests pass; verify-sanitized.sh passes; no stray sidecar processes
  or unexpected .hb files are written to ~/.config/mosaic/fleet/run.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RMoEx7hfdFGjUiCHuN1RRi

packages/mosaic/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@mosaicstack/mosaic",
-  "version": "0.0.36",
+  "version": "0.0.35",
   "repository": {
     "type": "git",
     "url": "https://git.mosaicstack.dev/mosaicstack/stack.git",

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

@@ -15,7 +15,6 @@ import {
   buildSystemdEnableCommand,
   buildSystemdShowCommand,
   buildTmuxListPanesCommand,
-  buildTmuxListSessionsCommand,
   classifySendResult,
   detectDrift,
   enableFleetUnits,
@@ -30,7 +29,6 @@ import {
   parseHeartbeat,
   parseSystemdShow,
   parseTmuxListPanes,
-  parseTmuxListSessions,
   registerFleetCommand,
   resolveFleetPaths,
   RUNTIME_ACCEPTABLE_COMMANDS,
@@ -1076,10 +1074,6 @@ describe('fleet ps — JSON output shape (FR-6)', () => {
           exitCode: 0,
         };
       }
-      if (fullArgs.includes('list-sessions')) {
-        // Only the roster agent session on the socket (no unmanaged sessions)
-        return { stdout: 'canary-pi\n', stderr: '', exitCode: 0 };
-      }
       return { stdout: '', stderr: '', exitCode: 0 };
     };
 
@@ -1123,15 +1117,11 @@ describe('fleet ps — JSON output shape (FR-6)', () => {
     expect(row.runtime).toBe('pi');
     expect(row.systemdActive).toBe('active');
     expect(row.systemdEnabled).toBe('disabled');
-
-    // managed/source fields for roster agents
-    expect(row.managed).toBe(true);
-    expect(row.source).toBe('roster');
   });
 });
 
 describe('fleet ps — command sequences issued', () => {
-  it('issues systemd show + tmux list-panes per agent, then list-sessions for socket discovery', async () => {
+  it('issues systemd show + tmux list-panes per agent', async () => {
     const home = await mkdtemp(join(tmpdir(), 'mosaic-fleet-'));
     const rosterPath = join(home, 'fleet', 'roster.yaml');
     await mkdir(join(home, 'fleet'), { recursive: true });
@@ -1145,10 +1135,6 @@ describe('fleet ps — command sequences issued', () => {
     const calls: string[][] = [];
     const runner: CommandRunner = async (command, args) => {
       calls.push([command, ...args]);
-      if ([command, ...args].join(' ').includes('list-sessions')) {
-        // Only the roster agent — no unmanaged sessions
-        return { stdout: 'coder0\n', stderr: '', exitCode: 0 };
-      }
       return {
         stdout: 'ActiveState=inactive\nSubState=dead\nUnitFileState=enabled\n',
         stderr: '',
@@ -1169,7 +1155,6 @@ describe('fleet ps — command sequences issued', () => {
       expect(calls).toEqual([
         buildSystemdShowCommand('coder0'),
         buildTmuxListPanesCommand('coder0', 'mosaic-factory'),
-        buildTmuxListSessionsCommand('mosaic-factory'),
       ]);
     } finally {
       console.log = origLog;
@@ -1178,258 +1163,6 @@ describe('fleet ps — command sequences issued', () => {
   });
 });
 
-describe('buildTmuxListSessionsCommand', () => {
-  it('builds exact list-sessions command with session_name format', () => {
-    expect(buildTmuxListSessionsCommand('mosaic-factory')).toEqual([
-      'tmux',
-      '-L',
-      'mosaic-factory',
-      'list-sessions',
-      '-F',
-      '#{session_name}',
-    ]);
-  });
-
-  it('uses DEFAULT_SOCKET_NAME when socket is omitted', () => {
-    const cmd = buildTmuxListSessionsCommand();
-    expect(cmd[2]).toBe('mosaic-factory');
-  });
-});
-
-describe('parseTmuxListSessions', () => {
-  it('splits newline-delimited session names', () => {
-    expect(parseTmuxListSessions('canary-pi\n_holder\nsome-adhoc\n')).toEqual([
-      'canary-pi',
-      '_holder',
-      'some-adhoc',
-    ]);
-  });
-
-  it('returns empty array for blank output', () => {
-    expect(parseTmuxListSessions('')).toEqual([]);
-    expect(parseTmuxListSessions('  \n  \n')).toEqual([]);
-  });
-
-  it('trims whitespace from each line', () => {
-    expect(parseTmuxListSessions('  canary-pi  \n  some-adhoc  \n')).toEqual([
-      'canary-pi',
-      'some-adhoc',
-    ]);
-  });
-});
-
-describe('fleet ps — unmanaged socket sessions', () => {
-  it('includes unmanaged session row flagged UNMANAGED and excludes _holder', async () => {
-    const home = await mkdtemp(join(tmpdir(), 'mosaic-fleet-'));
-    const rosterPath = join(home, 'fleet', 'roster.yaml');
-    await mkdir(join(home, 'fleet'), { recursive: true });
-    await writeFile(
-      rosterPath,
-      [
-        'version: 1',
-        'transport: tmux',
-        'agents:',
-        '  - name: canary-pi',
-        '    runtime: pi',
-        '    class: canary',
-      ].join('\n'),
-    );
-
-    const nowMs = Date.now();
-    const activityEpoch = Math.floor((nowMs - 10_000) / 1000);
-
-    const runner: CommandRunner = async (command, args) => {
-      const full = [command, ...args].join(' ');
-      if (full.includes('list-sessions')) {
-        // Socket has: canary-pi (roster), _holder (excluded), some-adhoc (unmanaged)
-        return { stdout: 'canary-pi\n_holder\nsome-adhoc\n', stderr: '', exitCode: 0 };
-      }
-      if (full.includes('list-panes')) {
-        return { stdout: `99999 bash 0 ${activityEpoch}\n`, stderr: '', exitCode: 0 };
-      }
-      if (full.includes('systemctl') && full.includes('show')) {
-        return {
-          stdout: 'ActiveState=inactive\nSubState=dead\nUnitFileState=unknown\n',
-          stderr: '',
-          exitCode: 0,
-        };
-      }
-      return { stdout: '', stderr: '', exitCode: 0 };
-    };
-
-    const lines: string[] = [];
-    const origLog = console.log;
-    console.log = (msg: string) => {
-      lines.push(msg);
-    };
-
-    const program = new Command();
-    program.exitOverride();
-    registerFleetCommand(program, { runner, mosaicHome: home });
-
-    try {
-      await program.parseAsync(['node', 'mosaic', 'fleet', 'ps', '--json']);
-    } finally {
-      console.log = origLog;
-      await rm(home, { recursive: true, force: true });
-    }
-
-    const json = JSON.parse(lines.join('')) as AgentPsRow[];
-    expect(Array.isArray(json)).toBe(true);
-
-    // Should have 2 rows: canary-pi (roster) + some-adhoc (unmanaged); _holder excluded
-    expect(json).toHaveLength(2);
-
-    // Roster agent comes first
-    const rosterRow = json[0]!;
-    expect(rosterRow.name).toBe('canary-pi');
-    expect(rosterRow.managed).toBe(true);
-    expect(rosterRow.source).toBe('roster');
-
-    // Unmanaged session comes second
-    const unmanagedRow = json[1]!;
-    expect(unmanagedRow.name).toBe('some-adhoc');
-    expect(unmanagedRow.managed).toBe(false);
-    expect(unmanagedRow.source).toBe('socket');
-    expect(unmanagedRow.runtime).toBe('unknown');
-
-    // _holder must not appear
-    expect(json.map((r) => r.name)).not.toContain('_holder');
-
-    // tenant_id and host must be present on unmanaged rows
-    expect(typeof unmanagedRow.tenant_id).toBe('string');
-    expect(unmanagedRow.tenant_id.length).toBeGreaterThan(0);
-    expect(typeof unmanagedRow.host).toBe('string');
-    expect(unmanagedRow.host.length).toBeGreaterThan(0);
-
-    // driftFlag must be false for unmanaged (no roster runtime to compare)
-    expect(unmanagedRow.driftFlag).toBe(false);
-  });
-
-  it('shows UNMANAGED flag in table output for unmanaged sessions', async () => {
-    const home = await mkdtemp(join(tmpdir(), 'mosaic-fleet-'));
-    const rosterPath = join(home, 'fleet', 'roster.yaml');
-    await mkdir(join(home, 'fleet'), { recursive: true });
-    await writeFile(
-      rosterPath,
-      [
-        'version: 1',
-        'transport: tmux',
-        'agents:',
-        '  - name: canary-pi',
-        '    runtime: pi',
-        '    class: canary',
-      ].join('\n'),
-    );
-
-    const runner: CommandRunner = async (command, args) => {
-      const full = [command, ...args].join(' ');
-      if (full.includes('list-sessions')) {
-        return { stdout: 'canary-pi\nsome-adhoc\n', stderr: '', exitCode: 0 };
-      }
-      if (full.includes('list-panes')) {
-        return { stdout: '0 bash 1 0\n', stderr: '', exitCode: 0 };
-      }
-      if (full.includes('systemctl') && full.includes('show')) {
-        return {
-          stdout: 'ActiveState=inactive\nSubState=dead\nUnitFileState=unknown\n',
-          stderr: '',
-          exitCode: 0,
-        };
-      }
-      return { stdout: '', stderr: '', exitCode: 0 };
-    };
-
-    const lines: string[] = [];
-    const origLog = console.log;
-    console.log = (msg: string) => {
-      lines.push(msg);
-    };
-
-    const program = new Command();
-    program.exitOverride();
-    registerFleetCommand(program, { runner, mosaicHome: home });
-
-    try {
-      await program.parseAsync(['node', 'mosaic', 'fleet', 'ps']);
-    } finally {
-      console.log = origLog;
-      await rm(home, { recursive: true, force: true });
-    }
-
-    const tableOutput = lines.join('\n');
-    // some-adhoc row must appear with UNMANAGED flag
-    expect(tableOutput).toMatch(/some-adhoc/);
-    expect(tableOutput).toMatch(/UNMANAGED/);
-    // canary-pi roster row must not have UNMANAGED
-    const rosterLine = lines.find((l) => l.includes('canary-pi'));
-    expect(rosterLine).toBeDefined();
-    expect(rosterLine).not.toMatch(/UNMANAGED/);
-  });
-
-  it('gracefully shows only roster rows when list-sessions fails (socket missing)', async () => {
-    const home = await mkdtemp(join(tmpdir(), 'mosaic-fleet-'));
-    const rosterPath = join(home, 'fleet', 'roster.yaml');
-    await mkdir(join(home, 'fleet'), { recursive: true });
-    await writeFile(
-      rosterPath,
-      [
-        'version: 1',
-        'transport: tmux',
-        'agents:',
-        '  - name: canary-pi',
-        '    runtime: pi',
-        '    class: canary',
-      ].join('\n'),
-    );
-
-    const runner: CommandRunner = async (command, args) => {
-      const full = [command, ...args].join(' ');
-      if (full.includes('list-sessions')) {
-        // Simulate socket missing
-        return { stdout: '', stderr: 'no server running on /tmp/...', exitCode: 1 };
-      }
-      if (full.includes('list-panes')) {
-        return { stdout: '12345 pi 0 0\n', stderr: '', exitCode: 0 };
-      }
-      if (full.includes('systemctl') && full.includes('show')) {
-        return {
-          stdout: 'ActiveState=inactive\nSubState=dead\nUnitFileState=enabled\n',
-          stderr: '',
-          exitCode: 0,
-        };
-      }
-      return { stdout: '', stderr: '', exitCode: 0 };
-    };
-
-    const lines: string[] = [];
-    const origLog = console.log;
-    console.log = (msg: string) => {
-      lines.push(msg);
-    };
-
-    const program = new Command();
-    program.exitOverride();
-    registerFleetCommand(program, { runner, mosaicHome: home });
-
-    try {
-      // Must not throw
-      await expect(
-        program.parseAsync(['node', 'mosaic', 'fleet', 'ps', '--json']),
-      ).resolves.toBeDefined();
-    } finally {
-      console.log = origLog;
-      await rm(home, { recursive: true, force: true });
-    }
-
-    const json = JSON.parse(lines.join('')) as AgentPsRow[];
-    // Only roster agent visible; no crash
-    expect(json).toHaveLength(1);
-    expect(json[0]!.name).toBe('canary-pi');
-    expect(json[0]!.managed).toBe(true);
-  });
-});
-
 describe('agent watch', () => {
   it('builds exact grouped-viewer creation command', () => {
     expect(

packages/mosaic/src/commands/fleet.ts

@@ -389,10 +389,6 @@ export interface AgentPsRow {
   driftFlag: boolean;
   /** active but UnitFileState=disabled */
   bootEnableWarning: boolean;
-  /** true = came from roster; false = found on socket but not in roster */
-  managed: boolean;
-  /** "roster" = defined in roster.yaml; "socket" = discovered via tmux list-sessions */
-  source: 'roster' | 'socket';
 }
 
 /**
@@ -435,26 +431,6 @@ export function buildTmuxListPanesCommand(
   ];
 }
 
-/**
- * Returns the tmux list-sessions command to enumerate all sessions on a socket.
- * Format: `tmux -L <socket> list-sessions -F '#{session_name}'`
- * Used to discover ad-hoc sessions that are not in the roster.
- */
-export function buildTmuxListSessionsCommand(socketName = DEFAULT_SOCKET_NAME): string[] {
-  return ['tmux', '-L', socketName, 'list-sessions', '-F', '#{session_name}'];
-}
-
-/**
- * Parse the output of `tmux list-sessions -F '#{session_name}'` into an array of session names.
- * Returns an empty array on empty/blank output.
- */
-export function parseTmuxListSessions(output: string): string[] {
-  return output
-    .split('\n')
-    .map((line) => line.trim())
-    .filter((line) => line.length > 0);
-}
-
 /**
  * Returns the heartbeat file path for an agent.
  */
@@ -921,9 +897,7 @@ export function registerFleetCommand(program: Command, deps: FleetCommandDeps =
 
   cmd
     .command('ps')
-    .description(
-      'Show real-time status for all roster agents and unmanaged socket sessions (systemd + tmux + heartbeat)',
-    )
+    .description('Show real-time status for all roster agents (systemd + tmux + heartbeat)')
     .option('--json', 'Print JSON array')
     .action(async (opts: { json?: boolean }) => {
       const commandOpts = cmd.opts<{ mosaicHome: string; roster?: string }>();
@@ -934,9 +908,6 @@ export function registerFleetCommand(program: Command, deps: FleetCommandDeps =
 
       const rows: AgentPsRow[] = [];
 
-      // Build the set of roster agent names for quick lookup when filtering socket sessions.
-      const rosterAgentNames = new Set(roster.agents.map((a) => a.name));
-
       for (const agent of roster.agents) {
         // systemd show
         const showResult = await runner(...splitCommand(buildSystemdShowCommand(agent.name)));
@@ -977,75 +948,9 @@ export function registerFleetCommand(program: Command, deps: FleetCommandDeps =
           heartbeat: hb,
           driftFlag,
           bootEnableWarning,
-          managed: true,
-          source: 'roster',
         });
       }
 
-      // Enumerate all live sessions on the socket to surface unmanaged (ad-hoc) sessions.
-      // If list-sessions fails (socket not up), silently skip — show roster rows only.
-      try {
-        const listSessionsResult = await runner(
-          ...splitCommand(buildTmuxListSessionsCommand(roster.tmux.socketName)),
-        );
-        if (listSessionsResult.exitCode === 0) {
-          const socketSessions = parseTmuxListSessions(listSessionsResult.stdout);
-          const holderSession = roster.tmux.holderSession;
-
-          for (const sessionName of socketSessions) {
-            // Skip roster agents (already in rows) and the holder session (infrastructure).
-            if (rosterAgentNames.has(sessionName) || sessionName === holderSession) {
-              continue;
-            }
-
-            // tmux list-panes for pane info
-            const panesResult = await runner(
-              ...splitCommand(buildTmuxListPanesCommand(sessionName, roster.tmux.socketName)),
-            );
-            const paneInfo = parseTmuxListPanes(panesResult.stdout, nowMs);
-
-            // heartbeat — try reading the .hb file using the same path convention
-            const hbFile = heartbeatPath(sessionName, activePaths.mosaicHome);
-            let hbContent: string | null = null;
-            try {
-              hbContent = await readFile(hbFile, 'utf8');
-            } catch {
-              hbContent = null;
-            }
-            const hb = parseHeartbeat(hbContent, nowMs);
-
-            // systemd — check if mosaic-agent@<name>.service exists (usually inactive for ad-hoc)
-            const showResult = await runner(...splitCommand(buildSystemdShowCommand(sessionName)));
-            const sysInfo = parseSystemdShow(showResult.stdout);
-
-            const bootEnableWarning =
-              sysInfo.ActiveState === 'active' && sysInfo.UnitFileState === 'disabled';
-
-            rows.push({
-              name: sessionName,
-              tenant_id,
-              host,
-              // runtime unknown — not in roster
-              runtime: 'unknown',
-              systemdActive: sysInfo.ActiveState,
-              systemdEnabled: sysInfo.UnitFileState,
-              paneAlive: !paneInfo.dead,
-              panePid: paneInfo.pid,
-              paneCommand: paneInfo.command,
-              idleSeconds: paneInfo.idleSeconds,
-              heartbeat: hb,
-              // No roster runtime to compare — drift is not meaningful for unmanaged sessions
-              driftFlag: false,
-              bootEnableWarning,
-              managed: false,
-              source: 'socket',
-            });
-          }
-        }
-      } catch {
-        // list-sessions failed (socket missing or permission error) — show roster rows only
-      }
-
       if (opts.json) {
         console.log(JSON.stringify(rows, null, 2));
         return;
@@ -1077,7 +982,6 @@ export function registerFleetCommand(program: Command, deps: FleetCommandDeps =
             ? `${Math.round(row.heartbeat.ageMs / 1000)}s/${row.heartbeat.health}`
             : `unknown`;
         const flags: string[] = [];
-        if (!row.managed) flags.push('UNMANAGED');
         if (row.driftFlag) flags.push('DRIFT');
         if (row.bootEnableWarning) flags.push('BOOT-ENABLE');