fix(qa-evidence,observer): reject placeholder metadata and replay-only learning; declare the docs atomic-write target

- materialize measures revision, runtime and cwd itself and rejects supplied
  values that differ (CI run wrote revision "HEAD" and runtime "bun"), and
  refuses learning checkpoints that replay the same probe, naming the fix.
- The docs write observer treats Claude Code's atomic temp for the authorized
  doc target as transient, so a temp renamed before its per-file watch no
  longer marks the observation incomplete (ship-docsync-completion flake).
  Per-file monitoring outside declared targets stays fail-closed.

test/qa-evidence.test.ts

@@ -49,11 +49,11 @@ test('native capture executes once, preserves exact JSON and stderr, and materia
   expect(JSON.parse(fs.readFileSync(path.join(f.root, 'exploration-001.json'), 'utf8'))).toEqual({
     observationCommand: 'first native command', observed, hypothesis: 'The successful boundary suggests testing the rejected input next.', nextCommand: 'second native command',
   });
-  f.json('annotations.json', { revision: 'revision', runtime: 'runtime', cwd: f.root, evidence: [], learning: [] });
+  f.json('annotations.json', { revision: 'revision', evidence: [], learning: [] });
   const rejected = f.run('materialize', f.root, 'annotations.json');
   expect(rejected.status).toBe(2);
   expect(receipt(rejected.stderr).message).toContain('need limits (non-empty string array)');
-  f.json('annotations.json', { revision: 'revision', runtime: 'runtime', cwd: f.root, limits: ['Only the declared contract was checked.'], evidence: [{ capture: '001', command: 'first native command', contract: 'README.md', expected: 'Declared exact result', classification: 'pass' }], learning: ['001'] });
+  f.json('annotations.json', { revision: 'revision', limits: ['Only the declared contract was checked.'], evidence: [{ capture: '001', command: 'first native command', contract: 'README.md', expected: 'Declared exact result', classification: 'pass' }], learning: ['001'] });
   const report = f.run('materialize', f.root, 'annotations.json');
   expect(report.status, report.stderr).toBe(0);
   const final = JSON.parse(fs.readFileSync(path.join(f.root, 'evidence.json'), 'utf8'));
@@ -274,3 +274,23 @@ test('a later capture requires a checkpoint anchored on the latest complete capt
   expect(final).toMatchObject({ runtime: `bun ${Bun.version}`, cwd: f.root });
   expect(final.learning).toEqual([{ observationCommand: first, hypothesis: 'The first observation makes the second input the riskiest next probe.', nextCommand: second('002') }]);
 });
+
+test('materialize rejects placeholder metadata and same-probe learning with the fix in the message', () => {
+  const f = fixture();
+  expect(f.capture('001', 'console.log(JSON.stringify({ step: 1 }))').status).toBe(0);
+  const command = (id: string) => `bun gstack-qa-evidence capture ${f.root} ${id} --timeout-ms 4000 -- probe same`;
+  expect(f.run('checkpoint', f.root, '001', '001', command('001'), 'Replaying the identical probe checks whether the first result is deterministic.', command('002')).status).toBe(0);
+  const row = { capture: '001', command: command('001'), contract: 'README.md', expected: 'step 1', classification: 'pass' };
+  f.json('annotations.json', { revision: 'fixture-revision', runtime: 'bun', limits: ['One probe.'], evidence: [row] });
+  const placeholder = f.run('materialize', f.root, 'annotations.json');
+  expect(placeholder.status).toBe(2);
+  expect(receipt(placeholder.stderr).message).toContain(`runtime must be "bun ${Bun.version}"`);
+  f.json('annotations.json', { revision: 'fixture-revision', limits: ['One probe.'], evidence: [row], learning: ['001'] });
+  const replay = f.run('materialize', f.root, 'annotations.json');
+  expect(replay.status).toBe(2);
+  expect(receipt(replay.stderr).message).toContain('checkpoint 001 replays the same probe');
+  f.json('annotations.json', { revision: 'fixture-revision', limits: ['One probe.'], evidence: [row] });
+  const selected = f.run('materialize', f.root, 'annotations.json');
+  expect(selected.status, selected.stderr).toBe(0);
+  expect(JSON.parse(fs.readFileSync(path.join(f.root, 'evidence.json'), 'utf8')).learning).toEqual([]);
+});