enhancement(#558): add liveness hints to all GSD spawn announcements (#566)

* enhancement(#558): add liveness hints to all GSD spawn announcements

Append '(runs in a subagent — no output until it returns, ~1–5 min; expected,
not a freeze)' inline to every ◆ Spawning… banner and subagent dispatch
instruction across 26 workflows. Silent subagents look identical to frozen
sessions — this note sets the expectation so users wait instead of killing
healthy in-progress work.

Changes:
- references/ui-brand.md: document liveness convention under Spawning Indicators
- 10 banner workflows: append liveness note to ◆ Spawning… lines in-place
- 18 subagent-only workflows: add print instruction with liveness phrase
- tests/spawn-liveness-banner.test.cjs: new test; fails if any workflow with
  subagent_type omits 'runs in a subagent'
- docs/USER-GUIDE.md: troubleshooting entry for frozen-looking spawns
- .changeset/558-spawn-liveness-banner.md: changeset fragment

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* fix(#558): add missing pr field to changeset fragment

The changeset lint requires pr: <NNN> in frontmatter; the fragment was
written without it, causing parse.cjs to reject it.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* fix(#558): address codex review — missed spawns and tighten test

- plan-phase.md: add liveness note to chunked outline planner and
  per-plan chunked planner banners (two missed ◆ Spawning… lines)
- quick.md: add liveness note to research banner and add missing
  display line before planner spawn in Step 5
- plan-review-convergence.md: add liveness note to initial planning
  and review-agent spawn Display lines
- docs-update.md: add Print instructions with liveness note before
  gsd-doc-verifier spawns in Phase 1 and Phase 2
- autonomous.md: add Print instruction with liveness note before
  background plan-phase agent dispatch in step 3b
- tests/spawn-liveness-banner.test.cjs: replace single file-level
  check with two assertions:
  (1) every ◆ Spawning… banner line carries the phrase on that line
  (2) every file with subagent_type contains the phrase somewhere
  The tighter test would have caught all five missed spawns.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* fix(#558): tighten spawn-liveness test regex to catch spawn-word-anywhere variants

Previous SPAWN_BANNER_RE only matched ◆ immediately followed by Spawning|spawning.
Replace with /◆[^\n]*\bspawning?\b/i which matches the spawn word anywhere on the
◆ line — catching "◆ Chunked mode: spawning outline planner..." and similar.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* fix(#558): rename changeset to PR number 566 and correct pr field

Changeset was filed as 558-spawn-liveness-banner.md (issue#) but the
convention is the PR number. Renamed to 566-spawn-liveness-banner.md
and updated pr: 558 → pr: 566 so release notes link to the right PR.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

docs/USER-GUIDE.md

@@ -1126,6 +1126,14 @@ Always read a file before editing it. Never call Edit or Write on a file you hav
 
 You ran `/gsd-new-project` but `.planning/PROJECT.md` already exists. This is a safety check. If you want to start over, delete the `.planning/` directory first.
 
+### A Command Looks Frozen After "Spawning..."
+
+If you see `◆ Spawning researcher...` (or any "Spawning…" line) and then nothing — no output, no spinner — for 1–5 minutes, **this is normal**. GSD subagents run in a separate context window; their work is invisible to the parent session while in progress. The liveness note on the spawn line confirms this: "(runs in a subagent — no output until it returns, ~1–5 min; expected, not a freeze)".
+
+**Do not interrupt the session.** Killing it discards the in-progress subagent work and forces you to restart that step. Wait for the result to appear. Research and planning agents routinely take 1–5 minutes; verification agents can take longer on large phases.
+
+**If it truly seems stuck** (>10 minutes with no result): check whether Claude Code's agent task is still active in the sidebar. If the task shows as completed but no output appeared, the result may have been lost in a context switch — run the command again.
+
 ### Context Degradation During Long Sessions
 
 Clear your context window between major commands: `/clear` in Claude Code. GSD is designed around fresh contexts -- every subagent gets a clean 200K window. If quality is dropping in the main session, clear and use `/gsd-resume-work` or `/gsd-progress` to restore state.