fix(ticket-085): isolate participant documentation

TODO.md

@@ -3,7 +3,8 @@
 ## Active tickets
 
 - [ ] [`ticket-085`](project/ticket-085/README.md) — scope documentation
-  acceptance criteria to their governed source ticket. Current state:
+  acceptance criteria to their governed source ticket and keep participant
+  Markdown in the communication lane only. Current state:
   `IN_PROGRESS / PUBLICATION`.
 - [ ] [`ticket-083`](project/ticket-083/README.md) — keep workspace comparison
   artifacts and caches outside analysed repository state. Current state:

src/extractors/docs-deterministic.ts

@@ -98,17 +98,27 @@ export async function extractDocumentationBaseline(
   const resolver = createMarkdownPathResolver(root);
 
   for (const file of options.files) {
+    const relative = relativePosix(root, file);
+    // Governed participant files are the canonical communication channel and
+    // are extracted by project-communication. Reading the same bytes again as
+    // generic documentation creates two records with different heuristic
+    // polarity, which can turn one statement into a blocking self-conflict.
+    if (isGovernedParticipantDocument(relative)) continue;
     try {
       const body = await readText(file, config.maxFileBytes);
       records.push(...convertDocument(root, file, body, await primePathMapper(resolver, body)));
     } catch (error) {
-      warnings.push(`${relativePosix(root, file)}: ${error instanceof Error ? error.message : String(error)}`);
+      warnings.push(`${relative}: ${error instanceof Error ? error.message : String(error)}`);
     }
   }
 
   return { records, warnings };
 }
 
+function isGovernedParticipantDocument(relativePath: string): boolean {
+  return /^project\/ticket-[0-9]+\/(?:ai|user)-[^/]+\.md$/i.test(relativePath);
+}
+
 /**
  * Documentation prose names files exactly the way TODO and CHANGELOG do, and
  * until now was the one Markdown converter that kept the shorthand. On

test/docs.test.ts

@@ -70,6 +70,39 @@ test('governed ticket documentation keeps acceptance criteria local to its sourc
     .every((record) => !record.statement.target.tickets.includes('AC-01')));
 });
 
+test('governed participant communication is not duplicated as documentation', async () => {
+  const root = await fs.mkdtemp(path.join(os.tmpdir(), 't2c-docs-participant-boundary-'));
+  const ticket = path.join(root, 'project', 'ticket-118');
+  const participant = path.join(ticket, 'ai-codex.md');
+  const readme = path.join(ticket, 'README.md');
+  await fs.mkdir(ticket, { recursive: true });
+  await fs.writeFile(participant, [
+    '---',
+    'participant-id: agent:codex',
+    'participant: codex',
+    'role: agent',
+    'ticket: ticket-118',
+    '---',
+    '# Participant',
+    '',
+    'Control must reject transport authority and must not bypass `subactor`.',
+  ].join('\n'));
+  await fs.writeFile(readme, [
+    '# Ticket 118',
+    '',
+    '- Control must reject transport authority in `config/adopt.json`.',
+  ].join('\n'));
+
+  const result = await extractDocumentationBaseline({
+    root,
+    files: [participant, readme],
+  }, makeConfig(root));
+
+  assert.equal(result.warnings.length, 0);
+  assert.ok(result.records.length > 0);
+  assert.ok(result.records.every((record) => record.source.path === 'project/ticket-118/README.md'));
+});
+
 test('deterministic documentation preserves Polish prohibition polarity', async () => {
   const root = await fs.mkdtemp(path.join(os.tmpdir(), 't2c-docs-prohibition-'));
   const readme = path.join(root, 'README.md');