feat(#2162): opt-in compact GSD-state format for the statusline (#2175)

* feat(#2162): opt-in compact GSD-state format for the statusline

New statusline.state_format config, enum full|compact (default full —
existing rendering untouched). "compact" renders the state segment as
"<version> · P<phase>/<total> · <status>", e.g. "v1.12 · P7/12 ·
executing" — dropping the milestone name and progress bar (the two
biggest width costs) and collapsing narrative statuses to a single
keyword. Per the #2162 approval conditions, the keyword set is the
canonical vocabulary from normalizeStateStatus() in state-document.cjs
(discussing/planning/executing/verifying/completed/paused) — no
parallel hand-rolled list, so the vocabularies can't drift — and the
canonical stuck state "paused" renders uppercase as PAUSED (no new
"blocked" lifecycle state). Statuses the normalizer passes through
unrecognized fall back to their first word capped at 16 chars.
Lifecycle scenes preserved: active_phase wins over the body phase
number, milestone completion renders "complete", idle-with-next-action
renders "next <action> <phases>".

Claude-Session: https://claude.ai/code/session_01Hme55Pvq6BhpgwBcyC5HAg

* docs(#2162): changeset fragment for PR #2175

* fix(#2162): review fixes — ENUM_KEYS coverage, cap boundary tests, changeset format

- register statusline.state_format in the fix-1628 coercion-bypass matrix
- 15/16/17-char boundary tests for the shortGsdStatus fallback cap
- changeset body ends with the (#2162) citation per house convention

Claude-Session: https://claude.ai/code/session_01Hme55Pvq6BhpgwBcyC5HAg

* fix(#2162): round-2 review fixes — scene exclusivity, direct config-set coverage

- compact renderer gates the milestone-complete scene behind the absence of
  an in-flight phase id, mirroring formatGsdState's if/else precedence
  (Scene 1 beats Scene 3); regression test covers the non-atomic
  active_phase + percent=100 STATE.md shape
- direct config-set accept/reject test for statusline.state_format plain
  strings (ENUM_KEYS matrix covers only the JSON coercion shapes)

Claude-Session: https://claude.ai/code/session_01Hme55Pvq6BhpgwBcyC5HAg

* test: regenerate golden-install-parity fixtures for the statusline hook change

Claude-Session: https://claude.ai/code/session_01Hme55Pvq6BhpgwBcyC5HAg

* fix(#2162): complete-scene gate matches formatGsdState exactly (+property tests)

Re-review Major: gating done on !phaseId held completion back for the
legacy phaseNum shape — formatGsdState reaches Scene 3 on percent=100
regardless of phaseNum, so compact must too. Gate is now !s.activePhase.
The phaseNum-only test now expects 'complete' and cross-checks the full
renderer; a parity test feeds identical inputs to both renderers.
Re-review Minor: shortGsdStatus gets fast-check property coverage
(totality, canonical fixed points, separator safety, fallback shape).
Golden fixtures regenerated for the hook byte change.

Claude-Session: https://claude.ai/code/session_01Hme55Pvq6BhpgwBcyC5HAg

docs/CONFIGURATION.md

@@ -453,6 +453,7 @@ If `.planning/` is in `.gitignore`, `commit_docs` is automatically `false` regar
 | `statusline.show_last_command` | boolean | `false` | Append `last: /<cmd>` suffix to the statusline showing the most recently invoked slash command. Opt-in; reads the active session transcript to extract the latest `<command-name>` tag (closes #2538) |
 | `statusline.context_position` | string | `"end"` | Position of the context-window meter. `"end"` (default) renders at line tail; `"front"` renders immediately after the model name so the meter stays visible in narrow terminals. Closes #2937 |
 | `statusline.show_context_tokens` | boolean | `false` | Append the absolute token count (e.g. `(156k)`) after the context meter's percentage. Sums input, cache-creation, cache-read, and output tokens from the hook payload — a broader basis than the meter's percentage (which excludes output tokens), so the two figures can diverge slightly. Opt-in; the meter is unchanged when the flag is absent |
+| `statusline.state_format` | string | `"full"` | Format of the GSD-state segment. `"full"` (default) is the existing rendering with milestone name and progress bar. `"compact"` renders `<version> · P<phase>/<total> · <status>` (e.g. `v1.12 · P7/12 · executing`) — drops the milestone name and bar, and collapses narrative statuses to the canonical keyword set from `normalizeStateStatus()` (`paused` — the canonical stuck state — renders uppercase as `PAUSED`) |
 | `statusline.show_git` | boolean | `false` | Append a git segment after the directory: current branch plus compact work-state markers (`+staged` `~unstaged` `?untracked` `↑ahead` `↓behind`, or `✓` when clean and in sync). One `git status --porcelain=v2` call per render; the segment is absent outside a git repo or when git is unavailable |
 
 The prompt injection guard hook (`gsd-prompt-guard.js`) is always active and cannot be disabled — it's a security feature, not a workflow toggle.