docs: restructure documentation into docs/ directory, slim README, add project .mcp.json

- README.md: reduced to overview + quick start + links to docs/
- docs/architecture.md: stack, design decisions, data models, key services
- docs/configuration.md: all env vars, docker-compose setup, production + security
- docs/development.md: dev workflow, CI/CD, migrations, release process
- docs/features.md: detailed feature breakdown + keyboard shortcuts
- docs/api-keys-and-mcp.md: API key management + Fable MCP install guide
- docs/sso-oauth.md: OAuth/OIDC setup (replaces docs/oauth-setup.md)
- docs/changelog.md: development history from summary.md
- Remove summary.md (content distributed across docs/)
- Remove docs/oauth-setup.md (superseded by docs/sso-oauth.md)
- .gitignore: add .mcp.json

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

docs/2026-03-23-fable-mcp-plan.md

@@ -6,6 +6,8 @@
 
 **Architecture:** Phase 1 adds bearer token auth to the existing Quart app (new `api_keys` table, updated `_check_auth`, settings UI tab). Phase 2 is a standalone `fable-mcp/` Python package using the `mcp[cli]` SDK that calls the Fable HTTP API via `httpx`. The two phases are sequential — Phase 2 can be built/tested independently using a write-scoped API key once Phase 1 is done.
 
+**Deployment decision:** `fable-mcp/` stays permanently inside the `fabledassistant` repo. It will always be versioned alongside the backend it targets. Future Task A will serve the package from the running Fable Docker image so users can install it directly from their instance.
+
 **Tech Stack:** Python 3.12, Quart (Phase 1); `mcp[cli]`, `httpx`, `python-dotenv` (Phase 2); Vue 3 + TypeScript (Settings UI); pytest for both.
 
 **Testing convention:** Phase 1 tests run via `docker compose run --rm app pytest tests/<file> -v`. Phase 2 tests run locally with `cd fable-mcp && pytest -v`. All Phase 1 tests are unit tests of pure functions — mock DB calls with `unittest.mock.AsyncMock`; never connect to a real database in tests.