fix(#1516): expose adaptive model_profile in /gsd-new-project AI Models prompt (#1654)

* fix(#1516): expose adaptive model_profile in /gsd-new-project AI Models prompt

Both onboarding paths (Step 2a auto-mode + Step 5 interactive) enumerated only
4 profiles (Balanced/Quality/Budget/Inherit), omitting 'adaptive' even though the
model catalog (model-catalog.json profiles) and docs/CONFIGURATION.md register 5.
Mirrors the proven /gsd:settings two-question split (#3784): Q1 routes between
Adaptive/Standard-tier/Inherit; Q2 (conditional on Q1=Standard) picks
Quality/Balanced/Budget — keeping every AskUserQuestion within the 4-option cap.
Both config-new-project example payloads now list adaptive. Regression cases
folded into the owning tests/new-project-mvp-prompt.test.cjs (per the
lint-regression-test-names ban on new top-level bug-NNNN files): each AI Models
prompt makes adaptive reachable, all 5 profiles reachable, 4-option cap honored,
both example enums include adaptive, brace balance. Workflow size baseline bumped
(new-project.md 62324 -> 66138 bytes; still well under the XL hard cap).

* chore(#1516): backfill changeset pr ref to 1654

.changeset/gallant-geese-run.md

@@ -0,0 +1,5 @@
+---
+type: Fixed
+pr: 1654
+---
+**`/gsd-new-project` AI Models prompt now exposes the `adaptive` model profile** — both onboarding paths (auto-mode and interactive) listed only Balanced/Quality/Budget/Inherit, so the `adaptive` profile (role-based cost optimization across Claude/Codex/Gemini/OpenRouter/local) was unreachable through `/gsd-new-project` despite being a first-class catalog entry and documented in CONFIGURATION.md. Both prompts now use the proven two-question split (Q1: Adaptive / Standard tier / Inherit; Q2: Quality / Balanced / Budget) already shipped for `/gsd:settings` (#3784), and both `config-new-project` example payloads list `adaptive`. (#1516)