fix(connect_to_device): probe OnlineChangeOption + try login() call shapes

Defensively iterates plausible signatures for IOnlineApplication.login()
across SP versions. Prior version hard-coded
'login(OnlineChangeOption.TryOnlineChange)' which fails on SP21+/SP22:

  - 'TryOnlineChange' enum member was removed
  - login() now requires (OnlineChangeOption, bool) -- two positional args

Concrete failure observed today on SP22 Patch 1:
  - First fallback raised: 'type' object has no attribute 'TryOnlineChange'
  - Second fallback raised: login() takes exactly 2 arguments (0 given)
  ...with the runtime actually reachable on port 11740. So a real call
  was waiting for the right arguments.

New approach:
  1) Discover OnlineChangeOption members at runtime via dir(); print them
     so future debug sessions see exactly what's exposed on this CODESYS.
  2) Try (enum, False) / (enum, True) / (enum,) for each candidate enum
     value, prioritising 'Try'-ish names then 'WithDownload' / others.
  3) Fall back to bool-only and no-arg for very old SPs.
  4) Log every attempt (DEBUG line) so a failure trace shows the full
     matrix that was tried.

Companion fixes for download_to_device, write_variable, etc. coming as
separate commits if their root cause is the same login API drift.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/scripts/connect_to_device.py

@@ -7,24 +7,66 @@ try:
     online_app, target_app = ensure_online_connection(primary_project)
     app_name = getattr(target_app, 'get_name', lambda: "Unknown")()
 
-    # Login to the device
+    # Login to the device. The login() signature shifted across SPs:
+    #   - Older: login() with no args, or login(OnlineChangeOption.TryOnlineChange)
+    #   - SP21+/SP22: login(OnlineChangeOption, bool) -- two required positional
+    #     args, with several enum members renamed (TryOnlineChange removed).
+    # Probe what's available, then try a sequence of plausible call shapes.
     print("DEBUG: Calling login() on online application...")
-
-    if hasattr(online_app, 'login'):
-        # Try with OnlineChangeOption if available
-        if hasattr(script_engine, 'OnlineChangeOption'):
-            try:
-                online_app.login(script_engine.OnlineChangeOption.TryOnlineChange)
-                print("DEBUG: Logged in with TryOnlineChange option.")
-            except Exception as e:
-                print("DEBUG: Login with OnlineChangeOption failed, trying plain login: %s" % e)
-                online_app.login()
-        else:
-            online_app.login()
-        print("DEBUG: Login successful.")
-    else:
+    if not hasattr(online_app, 'login'):
         raise TypeError("Online application does not support login().")
 
+    # Discover OnlineChangeOption members defensively. Different SPs expose
+    # different names. Build candidate enum values in priority order.
+    enum_candidates = []
+    if hasattr(script_engine, 'OnlineChangeOption'):
+        oc = script_engine.OnlineChangeOption
+        oc_members = sorted([m for m in dir(oc) if not m.startswith('_')])
+        print("DEBUG: OnlineChangeOption members: %s" % oc_members)
+        # Priority order: prefer "try"-ish (no-download), then "download" variants
+        for preferred in ('Try', 'TryOnlineChange', 'OnlineChangeOnly',
+                          'WithDownload', 'ForceDownload', 'None_', 'None'):
+            if preferred in oc_members:
+                try:
+                    enum_candidates.append((preferred, getattr(oc, preferred)))
+                except Exception:
+                    pass
+        # Append all remaining members as fallbacks
+        for m in oc_members:
+            if m not in [n for n, _ in enum_candidates]:
+                try:
+                    enum_candidates.append((m, getattr(oc, m)))
+                except Exception:
+                    pass
+
+    # Build call-shape candidates for login(): a list of (description, args-tuple).
+    call_shapes = []
+    for nm, val in enum_candidates:
+        call_shapes.append(("login(%s, False)" % nm, (val, False)))
+        call_shapes.append(("login(%s, True)" % nm, (val, True)))
+        call_shapes.append(("login(%s)" % nm, (val,)))
+    # Also try plain bools and no-arg as fall-backs (for very old SPs)
+    call_shapes.append(("login(False)", (False,)))
+    call_shapes.append(("login(True)", (True,)))
+    call_shapes.append(("login()", ()))
+
+    last_err = None
+    logged_in = False
+    for desc, args in call_shapes:
+        try:
+            online_app.login(*args)
+            print("DEBUG: %s succeeded" % desc)
+            logged_in = True
+            break
+        except Exception as e:
+            last_err = e
+            # Print only the short error to keep log readable
+            print("DEBUG: %s failed: %s: %s" % (desc, type(e).__name__, e))
+
+    if not logged_in:
+        raise RuntimeError("All login() call shapes failed. Last error: %s" % last_err)
+    print("DEBUG: Login successful.")
+
     # Check connection state
     state = "connected"
     if hasattr(online_app, 'application_state'):