🔒 refactor(bots): remove !login command and enforce OIDC-only auth

- Remove !login and !logout commands from all 16+ Matrix bots
- Remove login/logout references from all help/welcome messages
- Disable password login in Synapse (password_config.enabled: false)
- System is now OIDC-only via Mana Core authentication

Users must authenticate via "Sign in with Mana Core" in Element.
Existing bot access tokens remain valid.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

services/matrix-skilltree-bot/src/config/configuration.ts

@@ -17,13 +17,6 @@ export default () => ({
 
 export const HELP_MESSAGE = `<h2>Skilltree Bot - Befehle</h2>
 
-<h3>Authentifizierung</h3>
-<ul>
-<li><code>!login email passwort</code> - Anmelden</li>
-<li><code>!logout</code> - Abmelden</li>
-<li><code>!status</code> - Bot-Status anzeigen</li>
-</ul>
-
 <h3>Skills</h3>
 <ul>
 <li><code>!skills</code> - Alle Skills auflisten</li>