feat(fleet): inject persona contract at launch (A3b) (#664)

packages/mosaic/src/commands/compose-contract.spec.ts

@@ -164,4 +164,89 @@ describe('composeContract — overlay composer', () => {
     expect(composeContract('pi', fixture.home)).toContain('# pi runtime contract');
     expect(composeContract('codex', fixture.home)).not.toContain('# pi runtime contract');
   });
+
+  // ── Persona contract injection (A3b) ──────────────────────────────────────
+  // composeContract reads MOSAIC_AGENT_CLASS and injects the resolved persona
+  // (override-aware). Save/restore the env so these tests don't leak state.
+  describe('persona contract (A3b)', () => {
+    let prevClass: string | undefined;
+
+    beforeEach(() => {
+      prevClass = process.env['MOSAIC_AGENT_CLASS'];
+    });
+
+    afterEach(() => {
+      if (prevClass === undefined) delete process.env['MOSAIC_AGENT_CLASS'];
+      else process.env['MOSAIC_AGENT_CLASS'] = prevClass;
+    });
+
+    const seedBaseline = (klass: string, body: string): void => {
+      mkdirSync(join(fixture.home, 'fleet', 'roles'), { recursive: true });
+      writeFileSync(join(fixture.home, 'fleet', 'roles', `${klass}.md`), body);
+    };
+    const seedOverride = (klass: string, body: string): void => {
+      mkdirSync(join(fixture.home, 'fleet', 'roles.local'), { recursive: true });
+      writeFileSync(join(fixture.home, 'fleet', 'roles.local', `${klass}.md`), body);
+    };
+
+    it('injects the baseline persona when MOSAIC_AGENT_CLASS is set and a role file exists', () => {
+      seedBaseline('coder', '# Coder\n\n(`class: coder`)\n\nBASELINE-MANDATE: ship the lane.\n');
+      process.env['MOSAIC_AGENT_CLASS'] = 'coder';
+      const out = composeContract('claude', fixture.home);
+      expect(out).toContain('# Persona Contract (coder)');
+      expect(out).toContain('BASELINE-MANDATE');
+    });
+
+    it('OVERRIDE WINS at launch: roles.local persona is injected over baseline (AC-NS-7)', () => {
+      seedBaseline('coder', '# Coder\n\n(`class: coder`)\n\nBASELINE-MANDATE.\n');
+      seedOverride('coder', '# Coder (override)\n\n(`class: coder`)\n\nOVERRIDE-MANDATE.\n');
+      process.env['MOSAIC_AGENT_CLASS'] = 'coder';
+      const out = composeContract('claude', fixture.home);
+      expect(out).toContain('# Persona Contract (coder)');
+      expect(out).toContain('OVERRIDE-MANDATE');
+      expect(out).not.toContain('BASELINE-MANDATE');
+    });
+
+    it('does NOT inject a persona when MOSAIC_AGENT_CLASS is unset', () => {
+      seedBaseline('coder', '# Coder\n\n(`class: coder`)\n\nBASELINE-MANDATE.\n');
+      delete process.env['MOSAIC_AGENT_CLASS'];
+      const out = composeContract('claude', fixture.home);
+      expect(out).not.toContain('# Persona Contract');
+    });
+
+    it('does NOT inject (no throw) when MOSAIC_AGENT_CLASS names an unknown class', () => {
+      seedBaseline('coder', '# Coder\n\n(`class: coder`)\n\nBASELINE-MANDATE.\n');
+      process.env['MOSAIC_AGENT_CLASS'] = 'nonexistent';
+      expect(() => composeContract('claude', fixture.home)).not.toThrow();
+      expect(composeContract('claude', fixture.home)).not.toContain('# Persona Contract');
+    });
+
+    it('places the persona contract BEFORE the fleet comms block (identity, then peers)', () => {
+      seedBaseline('enhancer', '# Enhancer\n\n(`class: enhancer`)\n\nIMPROVE.\n');
+      mkdirSync(join(fixture.home, 'fleet'), { recursive: true });
+      writeFileSync(
+        join(fixture.home, 'fleet', 'roster.yaml'),
+        [
+          'agents:',
+          '  - name: orchestrator',
+          '    class: orchestrator',
+          '  - name: enhancer',
+          '    class: enhancer',
+          '',
+        ].join('\n'),
+      );
+      const prevName = process.env['MOSAIC_AGENT_NAME'];
+      try {
+        process.env['MOSAIC_AGENT_CLASS'] = 'enhancer';
+        process.env['MOSAIC_AGENT_NAME'] = 'enhancer';
+        const out = composeContract('claude', fixture.home);
+        expect(out).toContain('# Persona Contract (enhancer)');
+        expect(out).toContain('# Fleet Comms');
+        expect(out.indexOf('# Persona Contract')).toBeLessThan(out.indexOf('# Fleet Comms'));
+      } finally {
+        if (prevName === undefined) delete process.env['MOSAIC_AGENT_NAME'];
+        else process.env['MOSAIC_AGENT_NAME'] = prevName;
+      }
+    });
+  });
 });