Phase 6: Session-Management Verbesserungen

- Session Auto-Load bei App-Start (aktive Session + Nachrichten)
- agent_id Spalte in messages-Tabelle für Agent-Zuordnung
- DbMessage Interface erweitert (agent_id)
- Session-Compacting: compact_session() fasst alte Nachrichten zusammen
- Standard: 30 letzte Nachrichten behalten, Rest als Summary

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

src-tauri/src/db.rs

@@ -35,6 +35,7 @@ pub struct ChatMessage {
     pub role: String,  // "user", "assistant", "system"
     pub content: String,
     pub model: Option<String>,
+    pub agent_id: Option<String>,  // Agent der die Nachricht erzeugt hat
     pub timestamp: String,
 }
 
@@ -160,10 +161,13 @@ impl Database {
                 role TEXT NOT NULL,
                 content TEXT NOT NULL,
                 model TEXT,
+                agent_id TEXT,
                 timestamp TEXT NOT NULL,
                 FOREIGN KEY (session_id) REFERENCES sessions(id) ON DELETE CASCADE
             );
             CREATE INDEX IF NOT EXISTS idx_messages_session ON messages(session_id, timestamp);
+
+            "
             ",
         )?;
         Ok(())
@@ -517,19 +521,51 @@ impl Database {
         Ok(())
     }
 
+    /// Holt die zuletzt aktualisierte aktive Session
+    pub fn get_active_session(&self) -> SqlResult<Option<Session>> {
+        let result = self.conn.query_row(
+            "SELECT id, claude_session_id, title, working_dir, message_count,
+                    token_input, token_output, cost_usd, status, created_at, updated_at, last_message
+             FROM sessions WHERE status = 'active' ORDER BY updated_at DESC LIMIT 1",
+            [],
+            |row| {
+                Ok(Session {
+                    id: row.get(0)?,
+                    claude_session_id: row.get(1)?,
+                    title: row.get(2)?,
+                    working_dir: row.get(3)?,
+                    message_count: row.get(4)?,
+                    token_input: row.get(5)?,
+                    token_output: row.get(6)?,
+                    cost_usd: row.get(7)?,
+                    status: row.get(8)?,
+                    created_at: row.get(9)?,
+                    updated_at: row.get(10)?,
+                    last_message: row.get(11)?,
+                })
+            },
+        );
+        match result {
+            Ok(s) => Ok(Some(s)),
+            Err(rusqlite::Error::QueryReturnedNoRows) => Ok(None),
+            Err(e) => Err(e),
+        }
+    }
+
     // ============ Messages ============
 
     /// Speichert eine Nachricht
     pub fn save_message(&self, msg: &ChatMessage) -> SqlResult<()> {
         self.conn.execute(
-            "INSERT OR REPLACE INTO messages (id, session_id, role, content, model, timestamp)
-             VALUES (?1, ?2, ?3, ?4, ?5, ?6)",
+            "INSERT OR REPLACE INTO messages (id, session_id, role, content, model, agent_id, timestamp)
+             VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7)",
             params![
                 msg.id,
                 msg.session_id,
                 msg.role,
                 msg.content,
                 msg.model,
+                msg.agent_id,
                 msg.timestamp,
             ],
         )?;
@@ -539,7 +575,7 @@ impl Database {
     /// Lädt alle Nachrichten einer Session
     pub fn load_messages(&self, session_id: &str) -> SqlResult<Vec<ChatMessage>> {
         let mut stmt = self.conn.prepare(
-            "SELECT id, session_id, role, content, model, timestamp
+            "SELECT id, session_id, role, content, model, agent_id, timestamp
              FROM messages WHERE session_id = ?1 ORDER BY timestamp ASC"
         )?;
 
@@ -550,7 +586,8 @@ impl Database {
                 role: row.get(2)?,
                 content: row.get(3)?,
                 model: row.get(4)?,
-                timestamp: row.get(5)?,
+                agent_id: row.get(5)?,
+                timestamp: row.get(6)?,
             })
         })?.collect::<SqlResult<Vec<_>>>()?;
 
@@ -563,6 +600,83 @@ impl Database {
         Ok(())
     }
 
+    /// Zählt Nachrichten einer Session
+    pub fn count_messages(&self, session_id: &str) -> SqlResult<usize> {
+        self.conn.query_row(
+            "SELECT COUNT(*) FROM messages WHERE session_id = ?1",
+            params![session_id],
+            |row| row.get(0),
+        )
+    }
+
+    /// Kompaktiert eine Session: Behält die letzten N Nachrichten, fasst ältere zusammen
+    /// Gibt die Anzahl der kompaktierten Nachrichten zurück
+    pub fn compact_session(&self, session_id: &str, keep_last: usize) -> SqlResult<usize> {
+        let total = self.count_messages(session_id)?;
+        if total <= keep_last {
+            return Ok(0); // Nichts zu kompaktieren
+        }
+
+        let to_compact = total - keep_last;
+
+        // Alte Nachrichten holen (die kompaktiert werden sollen)
+        let mut stmt = self.conn.prepare(
+            "SELECT id, role, content FROM messages
+             WHERE session_id = ?1
+             ORDER BY timestamp ASC
+             LIMIT ?2"
+        )?;
+
+        let old_messages: Vec<(String, String, String)> = stmt.query_map(
+            params![session_id, to_compact as i64],
+            |row| Ok((row.get(0)?, row.get(1)?, row.get(2)?))
+        )?.collect::<SqlResult<Vec<_>>>()?;
+
+        if old_messages.is_empty() {
+            return Ok(0);
+        }
+
+        // Summary erstellen
+        let mut summary_parts: Vec<String> = Vec::new();
+        for (_, role, content) in &old_messages {
+            let preview = if content.len() > 200 {
+                format!("{}...", &content[..200])
+            } else {
+                content.clone()
+            };
+            summary_parts.push(format!("[{}] {}", role, preview));
+        }
+        let summary_content = format!(
+            "📦 **Kompaktierter Kontext** ({} Nachrichten)\n\n{}",
+            old_messages.len(),
+            summary_parts.join("\n\n---\n\n")
+        );
+
+        // IDs der alten Nachrichten
+        let old_ids: Vec<&str> = old_messages.iter().map(|(id, _, _)| id.as_str()).collect();
+
+        // Alte Nachrichten löschen
+        let placeholders: String = old_ids.iter().map(|_| "?").collect::<Vec<_>>().join(",");
+        let delete_sql = format!("DELETE FROM messages WHERE id IN ({})", placeholders);
+
+        let params: Vec<&dyn rusqlite::ToSql> = old_ids.iter().map(|id| id as &dyn rusqlite::ToSql).collect();
+        self.conn.execute(&delete_sql, params.as_slice())?;
+
+        // Summary-Nachricht einfügen (mit Timestamp vor allen anderen)
+        let summary_msg = ChatMessage {
+            id: uuid::Uuid::new_v4().to_string(),
+            session_id: session_id.to_string(),
+            role: "system".to_string(),
+            content: summary_content,
+            model: None,
+            agent_id: None,
+            timestamp: "1970-01-01T00:00:00Z".to_string(), // Ganz am Anfang
+        };
+        self.save_message(&summary_msg)?;
+
+        Ok(old_messages.len())
+    }
+
     // ============ Settings ============
 
     /// Speichert eine Einstellung
@@ -732,3 +846,22 @@ pub async fn clear_messages(app: AppHandle, session_id: String) -> Result<(), St
     let db = state.lock().unwrap();
     db.clear_messages(&session_id).map_err(|e| e.to_string())
 }
+
+/// Session kompaktieren — fasst alte Nachrichten zusammen
+#[tauri::command]
+pub async fn compact_session(
+    app: AppHandle,
+    session_id: String,
+    keep_last: Option<usize>,
+) -> Result<usize, String> {
+    let keep = keep_last.unwrap_or(30); // Standard: letzte 30 Nachrichten behalten
+    let state = app.state::<DbState>();
+    let db = state.lock().unwrap();
+    let compacted = db.compact_session(&session_id, keep).map_err(|e| e.to_string())?;
+
+    if compacted > 0 {
+        println!("📦 Session {} kompaktiert: {} Nachrichten zusammengefasst", session_id, compacted);
+    }
+
+    Ok(compacted)
+}

src-tauri/src/lib.rs

@@ -65,6 +65,7 @@ pub fn run() {
             db::save_message,
             db::load_messages,
             db::clear_messages,
+            db::compact_session,
         ])
         .setup(|app| {
             let handle = app.handle().clone();

src/lib/stores/app.ts

@@ -231,6 +231,7 @@ export interface DbMessage {
 	role: string;
 	content: string;
 	model: string | null;
+	agent_id: string | null;  // Agent der die Nachricht erzeugt hat
 	timestamp: string;
 }
 
@@ -242,6 +243,7 @@ export function messageToDb(msg: Message, sessionId: string): DbMessage {
 		role: msg.role,
 		content: msg.content,
 		model: msg.model || null,
+		agent_id: msg.agentId || null,
 		timestamp: msg.timestamp.toISOString(),
 	};
 }
@@ -253,6 +255,7 @@ export function dbToMessage(db: DbMessage): Message {
 		role: db.role as Message['role'],
 		content: db.content,
 		model: db.model || undefined,
+		agentId: db.agent_id || undefined,
 		timestamp: new Date(db.timestamp),
 	};
 }

src/routes/+layout.svelte

@@ -2,9 +2,25 @@
 	import '../app.css';
 	import { onMount, onDestroy } from 'svelte';
 	import { invoke } from '@tauri-apps/api/core';
-	import { isProcessing, agentCount, currentModel, sessionStats, initEventListeners, cleanupEventListeners } from '$lib/stores';
+	import { isProcessing, agentCount, currentModel, sessionStats, initEventListeners, cleanupEventListeners, currentSessionId, setMessagesFromDb, type DbMessage } from '$lib/stores';
 	import StopButton from '$lib/components/StopButton.svelte';
 
+	// Session-Typ vom Backend
+	interface Session {
+		id: string;
+		claude_session_id: string | null;
+		title: string;
+		working_dir: string | null;
+		message_count: number;
+		token_input: number;
+		token_output: number;
+		cost_usd: number;
+		status: string;
+		created_at: string;
+		updated_at: string;
+		last_message: string | null;
+	}
+
 	onMount(async () => {
 		await initEventListeners();
 
@@ -17,6 +33,32 @@
 		} catch (err) {
 			console.warn('Modell konnte nicht geladen werden:', err);
 		}
+
+		// Aktive Session automatisch laden (falls vorhanden)
+		try {
+			const activeSession: Session | null = await invoke('get_active_session');
+			if (activeSession) {
+				console.log('📂 Lade aktive Session:', activeSession.title);
+				$currentSessionId = activeSession.id;
+
+				// Session-Stats setzen
+				$sessionStats = {
+					totalTokensIn: activeSession.token_input,
+					totalTokensOut: activeSession.token_output,
+					totalCost: activeSession.cost_usd,
+					messageCount: activeSession.message_count,
+				};
+
+				// Nachrichten laden
+				const messages: DbMessage[] = await invoke('load_messages', { sessionId: activeSession.id });
+				if (messages.length > 0) {
+					setMessagesFromDb(messages);
+					console.log(`💬 ${messages.length} Nachrichten geladen`);
+				}
+			}
+		} catch (err) {
+			console.warn('Aktive Session konnte nicht geladen werden:', err);
+		}
 	});
 
 	onDestroy(async () => {