Add session stats and VACUUM on deletion

database.py: count_sessions(), db_size() (db+WAL+SHM), vacuum()
(VACUUM + wal_checkpoint(TRUNCATE) to actually reclaim space in WAL mode)

server.py: /api/sessions now returns total_sessions + db_size;
DELETE /api/sessions/<id> runs vacuum() after deletion

simtrace2_pysniff/server/database.py

@@ -41,6 +41,7 @@ class Database:
     def __init__(self, db_path=None):
         if db_path is None:
             db_path = DEFAULT_DB_PATH
+        self._db_path = db_path
         os.makedirs(os.path.dirname(db_path), exist_ok=True)
         self._conn = sqlite3.connect(db_path, check_same_thread=False)
         self._conn.execute('PRAGMA journal_mode=WAL')
@@ -74,6 +75,24 @@ class Database:
         self._conn.execute('DELETE FROM sessions WHERE id=?', (session_id,))
         self._conn.commit()
 
+    def count_sessions(self):
+        row = self._conn.execute('SELECT COUNT(*) FROM sessions').fetchone()
+        return row[0]
+
+    def db_size(self):
+        """Total on-disk size of the SQLite database (db + WAL + SHM)."""
+        total = 0
+        for suffix in ('', '-wal', '-shm'):
+            p = self._db_path + suffix
+            if os.path.exists(p):
+                total += os.path.getsize(p)
+        return total
+
+    def vacuum(self):
+        self._conn.execute('VACUUM')
+        self._conn.execute('PRAGMA wal_checkpoint(TRUNCATE)')
+        self._conn.commit()
+
     def get_session(self, session_id):
         row = self._conn.execute(
             'SELECT id, name, started, ended, mode FROM sessions WHERE id=?',

simtrace2_pysniff/server/server.py

@@ -126,7 +126,11 @@ class RequestHandler(BaseHTTPRequestHandler):
 
     def _handle_list_sessions(self):
         sessions = self.db.list_sessions()
-        self._send_json({'sessions': sessions})
+        self._send_json({
+            'sessions': sessions,
+            'total_sessions': self.db.count_sessions(),
+            'db_size': self.db.db_size(),
+        })
 
     def _handle_get_session(self, session_id, params):
         session = self.db.get_session(session_id)
@@ -192,6 +196,7 @@ class RequestHandler(BaseHTTPRequestHandler):
         if self.capture.session_id == session_id:
             self.capture.stop_session()
         self.db.delete_session(session_id)
+        self.db.vacuum()
         self._send_json({'ok': True})
 
     def _handle_search(self, session_id, query):