Validate username and password in Connect dialog too

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

app_state.py

@@ -8,7 +8,7 @@ so later rebinding would only ever be seen by the module that did it.
 import configparser
 import os
 
-VERSION = "0.0.0.099"
+VERSION = "0.0.0.100"
 PROPERTIES_FILE = os.path.join(os.path.dirname(os.path.abspath(__file__)), "editor.properties")
 DEFAULT_GRID_SIZE = 10
 DEFAULT_ADD_TIMESTAMP = True

connect_dialog.py

@@ -93,6 +93,12 @@ class ConnectDialog:
         if not host:
             self._status_label.config(text="Host is required", foreground="#c00000")
             return
+        if not user:
+            self._status_label.config(text="Username is required", foreground="#c00000")
+            return
+        if not password:
+            self._status_label.config(text="Password is required", foreground="#c00000")
+            return
 
         try:
             port_int = int(port)