fix(3347): surface auto-build state via graphifyStatus; trim planner edits to free size budget

agents/gsd-planner.md was 49,316 chars after the initial PR; the
planner-decomposition <48K test was passing on main at 49,150 chars (just under
the 49152 limit). My addition pushed it over.

Restructure: instead of teaching the planner agent to read .last-build-status.json
directly, fold the auto-build state into graphifyStatus()'s existing `stale: true`
signal. The planner's existing rule ("if stale: true, treat as approximate") fires
correctly for failed and in-flight auto-builds — no new planner-side prompt content
needed. The full state is exposed under `last_build_auto_update` for callers that
want exit_code / duration_ms / commit-sha context.

- get-shit-done/bin/lib/graphify.cjs: graphifyStatus() reads
  .planning/graphs/.last-build-status.json; OR-folds status in {failed, running}
  into the existing stale signal; exposes last_build_auto_update field
- agents/gsd-planner.md: revert the auto-update awareness paragraph (49,524 → 49,150)
- agents/gsd-phase-researcher.md: revert the parallel paragraph for consistency
- get-shit-done/references/planner-graphify-auto-update.md: rewrite to document
  the graphifyStatus seam instead of planner-side prompt instructions
- tests/feat-3347-graphify-auto-update-config.test.cjs: 4 new graphifyStatus
  tests pinning the failed/running/ok/missing matrix
- tests/feat-3347-graphify-auto-update-hook.test.cjs: bump per-spawn timeout
  5s → 30s and wait-deadline 5s → 15s to absorb cold-start latency under
  parallel-test-file load (full suite runs many *.test.cjs concurrently)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

agents/gsd-phase-researcher.md

@@ -637,8 +637,6 @@ node "$HOME/.claude/get-shit-done/bin/gsd-tools.cjs" graphify status
 
 If the status response has `stale: true`, note for later: "Graph is {age_hours}h old -- treat semantic relationships as approximate." Include this annotation inline with any graph context injected below.
 
-If `.planning/graphs/.last-build-status.json` exists, also load @get-shit-done/references/planner-graphify-auto-update.md — it covers how to surface the most recent auto-build state (running / failed / stale `head_at_build`). Opt-in via `graphify.auto_update` (default false, #3347); silent if the file is absent.
-
 Query the graph for each major capability in the phase scope (2-3 queries per D-05, discovery-focused):
 
 ```bash

agents/gsd-planner.md

@@ -892,8 +892,6 @@ node "$HOME/.claude/get-shit-done/bin/gsd-tools.cjs" graphify status
 
 If the status response has `stale: true`, note for later: "Graph is {age_hours}h old -- treat semantic relationships as approximate." Include this annotation inline with any graph context injected below.
 
-If `.planning/graphs/.last-build-status.json` exists, load @get-shit-done/references/planner-graphify-auto-update.md for auto-build state surfacing (opt-in, #3347).
-
 Query the graph for phase-relevant dependency context (single query per D-06):
 
 ```bash