feat: add Obsidian CLI API service

- Add Docker image for the official Obsidian desktop app and CLI.

- Start Obsidian headlessly with Xvfb and DBus setup.

- Expose a safe structured HTTP command API without shell execution.

- Add JWT-based vault, path, and command authorization.

- Support single-vault and multi-vault container mounts.

- Add TypeScript SDK helpers for Obsidian CLI commands.

- Add n8n community node package with Obsidian operations.

- Add docs, compose config, tests, and production image workflow.

.dockerignore

@@ -0,0 +1,13 @@
+.git
+.venv
+__pycache__
+.pytest_cache
+.ruff_cache
+.env
+vault
+*.pyc
+node_modules
+sdk/typescript/node_modules
+sdk/typescript/dist
+packages/*/node_modules
+packages/*/dist