Initial commit: 5 MCP servers for Mail, Calendar, Contacts, Files, Notes

Self-hosted MCP servers with OAuth client_credentials auth.
Each server connects to a different backend:
- Mail: reads Maildir IMAP backups
- Calendar/Tasks: CalDAV against Radicale
- Contacts: CardDAV against Radicale
- Files: WebDAV against oCIS
- Notes: Joplin REST API

Credentials externalized to config.json (not in repo).

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

tokens.json.example

@@ -0,0 +1,10 @@
+{
+  "stefan": {
+    "token": "REPLACE_WITH_RANDOM_SECRET",
+    "label": "Stefan"
+  },
+  "kati": {
+    "token": "REPLACE_WITH_RANDOM_SECRET",
+    "label": "Kati"
+  }
+}