Feature: Claude Assistent Chat in TaskMate

Neuer Tab "Assistent" mit interaktiver Claude Code Session:
- Chat-UI mit Session-Verwaltung (History, neue/alte Sessions)
- Claude CLI als Child-Process auf dem Host (interaktiv, mit Rueckfragen)
- Streaming-Output per Socket.io
- Nur fuer autorisierte User (Hendrik, Monami)
- 30 Min Inaktivitaets-Timeout
- Task-Uebergabe: Button im Task-Modal sendet Aufgabe an Assistenten
- Chat-Verlauf wird in DB gespeichert

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

backend/database.js

@@ -753,6 +753,32 @@ function createTables() {
     END
   `);
 
+  // Assistant Sessions (Claude-Assistent)
+  db.exec(`
+    CREATE TABLE IF NOT EXISTS assistant_sessions (
+      id INTEGER PRIMARY KEY AUTOINCREMENT,
+      user_id INTEGER NOT NULL,
+      title TEXT DEFAULT 'Neue Session',
+      status TEXT DEFAULT 'active',
+      task_context TEXT,
+      created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
+      ended_at DATETIME,
+      FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE
+    )
+  `);
+
+  // Assistant Messages
+  db.exec(`
+    CREATE TABLE IF NOT EXISTS assistant_messages (
+      id INTEGER PRIMARY KEY AUTOINCREMENT,
+      session_id INTEGER NOT NULL,
+      role TEXT NOT NULL,
+      content TEXT NOT NULL,
+      created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
+      FOREIGN KEY (session_id) REFERENCES assistant_sessions(id) ON DELETE CASCADE
+    )
+  `);
+
   // Indizes für Performance
   db.exec(`
     CREATE INDEX IF NOT EXISTS idx_tasks_project ON tasks(project_id);
@@ -785,6 +811,9 @@ function createTables() {
     CREATE INDEX IF NOT EXISTS idx_details_type ON contact_details(type);
     CREATE INDEX IF NOT EXISTS idx_interactions_contact ON contact_interactions(contact_id);
     CREATE INDEX IF NOT EXISTS idx_interactions_date ON contact_interactions(interaction_date);
+    -- Assistant-Indizes
+    CREATE INDEX IF NOT EXISTS idx_assistant_messages_session ON assistant_messages(session_id);
+    CREATE INDEX IF NOT EXISTS idx_assistant_sessions_user ON assistant_sessions(user_id);
   `);
 
   logger.info('Datenbank-Tabellen erstellt');