docs: scaffold guide and API indexes

docs/scratchpads/DOCS-IA-002-catalog-audit.md

@@ -17,6 +17,7 @@
 - [x] Write human-readable catalog/audit report.
 - [x] Verify report formatting and scope.
 - [x] Commit audit artifacts without unrelated working-tree changes.
+- [x] Scaffold audience, architecture, and API indexes without moving legacy content.
 
 ## Initial findings
 
@@ -29,6 +30,7 @@
 - TUI documents reference missing `packages/cli` and a missing historical worktree; current TUI code is under `packages/mosaic`.
 - `docs/openapi-tess.yaml` parses as OpenAPI 3.1 with 17 paths, but remains a legacy root-level Tess-scoped contract rather than the full API SSOT.
 - `.gitignore` ignores `docs/reports/`, conflicting with the new documentation contract; the audit report must be force-added and ignore remediation deferred to a separate change.
+- The scaffold slice adds `USER-GUIDE/README.md`, `ADMIN-GUIDE/README.md`, `ADMIN-GUIDE/security/README.md`, `DEVELOPER-GUIDE/README.md`, `DEVELOPER-GUIDE/architecture/README.md`, and `API/README.md`; legacy pages and `SITEMAP.md` remain unchanged.
 
 ## Method
 
@@ -58,3 +60,4 @@
 | Scoped commit               | PASS — audit plan, report, and scratchpad committed together; `.mosaic/orchestrator/*` remains outside the commit                                  |
 | Report formatting and scope | PASS — `pnpm exec prettier --ignore-path /dev/null --check` passed; ignored report path identified and force-add is required                       |
 | Commit hook behavior        | FINDING — lint-staged emitted an ignored `docs/reports` path error during commit even though the report was force-staged; remediation remains open |
+| Index scaffold              | PASS — six indexes formatted, all new Markdown/wikilinks resolve, target directories exist, and legacy pages plus `SITEMAP.md` were not changed    |