feat(board): session attention, Discord rows, task attribution and relaunch activity (rows 18, 22, #1511, #1512)

One cumulative control-board, webui and seat state. The four rows edit the
same files (scan.mjs, page.html, README.md, app.js), so they land together,
each on its own receipt:

- Row 18, Discord connector rows on the board (#1509): R3 approved by
  Darkwing and Dewey, Gitea comment 26257, manifest 254403b8. Jason
  accepted the visual test.
- Row 22, board attention status (#1503): Filbert approved R1, comment
  26248, manifest e40b58ec; restart receipt 26249.
- #1511, task attribution (row 6 code phase): R2 approved by Filbert and
  Dewey, manifest d4c96395. docs/TOOLS.md carries the approved --by usage
  line (tools-usage.patch 86bcba3c).
- #1512, relaunch activity (row 6 pilot): R1 approved by Darkwing and
  Dewey, candidate manifest 47769fad. All seven source files match it.

Row 16, internal development bootstrap (#1510): the seven files outside
shared records match Filbert's R1 pins, receipt 26204 (agents/researcher/*,
scripts/test-darkwing-launch.mjs, the bootstrap plan).

packages/webui/src/public/app.js is committed at its #1512 R1 pin ce7d79a4.
The working copy holds Dewey's unreviewed return-flow candidate on top of
that, and it stays uncommitted.

Also: the four row briefs and Darkwing's evidence records under
agents/darkwing/work, including the 2026-09-26 tree manifest and the #1512
re-run against 21e3e908. Serial acceptance command: 397/397, three runs.
The failures that only show when tests run concurrently are in #1509 engine
tests, and they reproduce on clean HEAD.

Suites on the exact staged tree: config 24, task 90, foundation 43,
conductor 17, release 14, auth 15, discord 63; package union 397/397
(serial); test-darkwing-launch 5/5.

Shared records (BUILD-LOG, QUEUE, CURRENT, DEFERRED, SESSIONS, AGENTS.md,
agents/README.md) follow in Sage's records commit.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

packages/webui/tests/fixture.mjs

@@ -4,7 +4,7 @@ import { mkdtempSync, mkdirSync, writeFileSync, rmSync } from 'node:fs';
 import { tmpdir } from 'node:os';
 import { join } from 'node:path';
 import { startServer as startBoard } from '../../control-board/src/serve.mjs';
-import { makeRegistration, writeRegistration } from '../../seat/src/seat.mjs';
+import { makeRegistration, writeRegistration, updateTask } from '../../seat/src/seat.mjs';
 import { startServer } from '../src/serve.mjs';
 export const close = server => new Promise(resolve => { server.close(resolve); server.closeIdleConnections(); });
 export async function fixture() {
@@ -14,7 +14,7 @@ export async function fixture() {
   const captures = [];
   for (const [agent, project, state] of [['agent1', 'proj', 'waiting'], ['agent2', 'proj', 'working'], ['agent3', 'other', 'error'], ['agent4', 'other', 'offline']]) {
     const sessionsDir = join(root, agent); mkdirSync(sessionsDir);
-    const assistant = { role: 'assistant', model: 'fixture-model', provider: 'fixture-provider', stopReason: state === 'error' ? 'error' : 'stop', content: [{ type: 'text', text: 'done? <script>window.injected=true</script>' }] };
+    const assistant = { role: 'assistant', model: 'fixture-model', provider: 'fixture-provider', stopReason: state === 'error' ? 'error' : 'stop', content: [{ type: 'text', text: (state === 'waiting' ? 'Input needed: ' : '') + 'done? <script>window.injected=true</script>' }] };
     const lines = [
       { type: 'session', id: agent, timestamp: '2026-09-01T00:00:00Z', cwd: '/fixture/workspace' },
       { type: 'message', timestamp: '2026-09-01T00:00:01Z', message: { role: 'user', content: [{ type: 'text', text: 'Build the fixture task' }] } },
@@ -23,7 +23,11 @@ export async function fixture() {
     if (state === 'working') lines.push({ type: 'message', timestamp: '2026-09-01T00:00:03Z', message: { role: 'user', content: [{ type: 'text', text: 'continue' }] } });
     writeFileSync(join(sessionsDir, 's.jsonl'), lines.map(l => JSON.stringify(l)).join('\n') + '\n');
     specs.push({ agent, project, sessionsDir, tmux: { session: agent } });
-    if (agent === 'agent1') writeRegistration(seatsDir, makeRegistration({ resolved: { seat: agent, project, sessionsDir, seatDir: sessionsDir, launchScript: join(root, 'unused.sh'), layout: 'repo', defaultWorkspace: '/fixture/workspace' }, task: 'Registered fixture task', tmux: { session: agent, socket: null }, pid: process.pid }));
+    if (agent === 'agent1') {
+      writeRegistration(seatsDir, makeRegistration({ resolved: { seat: agent, project, sessionsDir, seatDir: sessionsDir, launchScript: join(root, 'unused.sh'), layout: 'repo', defaultWorkspace: '/fixture/workspace' }, task: 'Registered fixture task', tmux: { session: agent, socket: null }, pid: process.pid }));
+      // #1511: the same path `mosaic seat task --by` takes, on the fixture record only.
+      updateTask(seatsDir, agent, 'Registered fixture task', { layout: 'repo', setBy: 'fixture-setter' });
+    }
   }
   const board = await startBoard({ port: 0, specs, seatsDir, boardDir: join(root, 'board'), isAlive: tmux => tmux.session !== 'agent4', isPidAlive: () => true,
     exec: (file, args) => { captures.push({ file, args }); return { status: exitCode, stdout: 'fixture transport', stderr: exitCode ? 'fixture refusal <unsafe>' : '' }; },