Add shared bible submodule, rename local bible to bible-local

- Add bible.git as submodule at bible/
- Rename bible/ → bible-local/ (project-specific architecture)
- Update CLAUDE.md to reference both bible/ and bible-local/
- Add AGENTS.md for Codex with same structure

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

bible-local/governance/documentation-policy.md

@@ -0,0 +1,20 @@
+# Documentation Policy
+
+## Purpose
+
+This policy defines how architectural knowledge is captured and maintained.
+
+## Mandatory Rules
+
+- Record every architecture decision in the Bible before or together with implementation.
+- Use English for all architecture documentation.
+- Keep only current architecture in active sections.
+- When a solution is replaced, update or remove obsolete guidance in the same change.
+- Keep architecture details centralized in `bible/`; other top-level docs should only reference it.
+
+## Change Workflow
+
+1. Update the relevant file(s) in `bible/architecture/`.
+2. If behavior changed, add or update a decision note in `bible/decisions/`.
+3. Remove duplicated or outdated statements from non-Bible docs.
+4. Validate consistency against code paths in `internal/api`, `internal/ingest`, and `internal/repository`.