feat(docs): grounded NLQA + support surface + auto-generated docs index

.github/workflows/docs-index.yml

@@ -0,0 +1,20 @@
+name: docs-index-fresh
+on:
+  push:
+    paths: ['docs/contract-additions/**', 'docs/surfaces/README.md', 'tools/build_docs_index.py', 'docs/surfaces/data/docs-index.json']
+  pull_request:
+    paths: ['docs/contract-additions/**', 'docs/surfaces/README.md', 'tools/build_docs_index.py', 'docs/surfaces/data/docs-index.json']
+jobs:
+  fresh:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with: { python-version: '3.11' }
+      - name: Regenerate the grounded docs index from source
+        run: python tools/build_docs_index.py
+      - name: Fail if the committed index drifted from source
+        run: |
+          if ! git diff --exit-code docs/surfaces/data/docs-index.json; then
+            echo "::error::docs-index.json is stale — run tools/build_docs_index.py and commit"; exit 1
+          fi

docs/surfaces/README.md

@@ -43,6 +43,9 @@ the real SociOS/GNOME chrome (top bar, launcher card) so they read as in-shell,
 - **`lampstand-launcher.html`** — Tier 2, *actionable*. The Spotlight replacement: natural
   language → typed intents/entities/relations (the annotation tree) → **governed actions**
   (purpose-bound, consent-gated, receipted), ranked by sherlock (IR). Not web search — typed acts.
+- **`docs-support.html`** — Tier 2, *grounded NLQA + support*. Answers only from the
+  auto-generated docs index (`tools/build_docs_index.py`), cites every source, and **abstains**
+  to support when a question isn't in the docs. A CI drift-guard keeps the index fresh from source.
 - **`model-governance.html`** — Tier 2, *regulated model registry*. Business targets (fraud/churn/
   credit/AML/propensity) with champion-vs-challenger, historic version comparison, PSI drift, and the
   DataClass classifiers per target. Model risk management as a witness surface.