web UI: playbook clip picker has no harness section until the New Session sheet has been opened once

[edwin-zvs]

The Playbook clip picker builds its harness rows from state.harnesses:

function playbookHarnessCandidates() {
  return state.harnesses.map((h) => { … clip: `@{harness:${name}}` … });
}
function playbookClipRootRows(query) {
  …
  const harnessCount = state.harnesses.length;
  if (harnessCount) cats.push({ type: "category", group: "harness", count: harnessCount });
  …
}

(crates/daemon/assets/index.html ~lines 8873–8908 @ ad47152)

But state.harnesses is only ever populated inside the New Session dialog:

async function openNewSessionDialog() {
  …
  harnesses = await rpc("harness.list", null);
  state.harnesses = Array.isArray(harnesses) ? harnesses : [];

(index.html ~line 15255)

On a fresh page load it is [], so the picker shows sessions only: no harness rows in the relevance section, and the harness ▸ category row is suppressed entirely — which also makes the harness submenu unreachable. @{harness:…} cannot be inserted from the web UI at all, even though the empty-state help right above the editor advertises it ("@{harness:name} delegates").

Repro

1. Load the web UI fresh, open a session's Playbook.
2. Type @.

Observed — root rows are sessions plus one category:

["clip","clip","separator","category:session"]
state.harnesses.length === 0

3. Open + new session, then cancel it. Type @ again:

["clip","clip","clip","clip","clip","separator","category:session","category:harness"]
state.harnesses → ["agy","claude","codex","grok","hermes","kimi","opencode","pi","shell","smith"]

The TUI's picker shows both categories unconditionally (session (3) ▸, harness (10) ▸).

Expected

harness.list is fleet state, not New-Session-dialog state. Fetch it on connect (alongside the session list) and refresh it on reconnect, so any consumer — the clip picker today, others later — sees it.

Acceptance criteria

• Typing @ in a freshly loaded web UI offers harness clips and the harness ▸ category, with no prior visit to the New Session sheet.
• The harness list survives a websocket reconnect.
• The New Session dialog keeps working from the shared state (no double fetch required).

Found during a hands-on UX audit of the Playbook in the TUI and web UI.