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.

packages/n8n-nodes-obsidian-api/README.md

@@ -0,0 +1,79 @@
+# n8n-nodes-obsidian-api
+n8n community-node package for the Obsidian API Docker service.
+
+It talks to the HTTP API, which then runs the **official Obsidian CLI** against mounted vaults. The node sends structured `args` arrays only. It does not send shell commands.
+
+## Nodes
+
+### Obsidian API
+
+Resources:
+- **Note**
+  - Create
+  - Read
+  - Append
+  - Prepend
+  - Delete
+  - Rename
+  - List Files
+- **Daily Note**
+  - Append
+  - Prepend
+  - Read
+  - Path
+- **Search**
+  - Search
+  - Search With Context
+- **Vault**
+  - Info
+  - List Vaults
+- **Raw Command**
+  - Safe args-array escape hatch for any official CLI command
+
+## Credentials
+Credential type: **Obsidian API**
+
+Fields:
+- **Base URL**: e.g. `http://obsidian-api:8080`
+- **API Token**: JWT created with `scripts/create_jwt.py`
+- **Default Vault**: optional, e.g. `work`
+
+## Multi-vault
+Set the `Vault` field on a node to override the credential default vault.
+
+The node sends this as the official CLI prefix:
+```text
+vault=work
+```
+
+Raw command example:
+```json
+["vault=work", "read", "path=Inbox/Note.md"]
+```
+
+## Local install in self-hosted n8n
+From this repo:
+```bash
+cd packages/n8n-nodes-obsidian-api
+npm install --ignore-scripts
+npm run build
+npm pack
+```
+
+Then install the generated `.tgz` in your n8n custom extensions setup.
+
+For Docker-based n8n, one common setup is mounting this package into n8n's custom extensions directory and setting:
+```env
+N8N_CUSTOM_EXTENSIONS=/home/node/.n8n/custom
+```
+
+Exact installation depends on your n8n deployment.
+
+## Development
+```bash
+npm install --ignore-scripts
+npm run typecheck
+npm run build
+```
+
+`--ignore-scripts` avoids local native builds from n8n transitive dependencies on unsupported bleeding-edge Node versions. Use the Node version recommended by your n8n release for production builds.