diff --git a/pyproject.toml b/pyproject.toml
index 6c781a8..2d9428d 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -72,3 +72,19 @@ markers = [
     "installer: Tests verifying installer and packaging",
     "live: End-to-end tests requiring real user credentials",
 ]
+
+[tool.ruff]
+line-length = 120
+target-version = "py310"
+extend-exclude = ["legacy", ".venv"]
+
+[tool.ruff.lint]
+# Bug-catching rules only, so CI gives a real signal today.
+#   E9  - syntax / IO errors        F63 - comparison & assert mistakes
+#   F7  - misplaced statements      F82 - undefined names
+#   F811 - redefinition of an in-use name
+# Style and modernization rules (UP, I, BLE, S, SIM, RUF) are intentionally
+# left off: the codebase currently has ~1200 such findings, and enabling them
+# wholesale would keep CI red instead of catching defects. Burn them down in
+# a dedicated pass, then extend this list.
+select = ["E9", "F63", "F7", "F82", "F811"]
diff --git a/scripts/live_provision_and_validate.py b/scripts/live_provision_and_validate.py
index 7c49a5e..5617cab 100644
--- a/scripts/live_provision_and_validate.py
+++ b/scripts/live_provision_and_validate.py
@@ -14,7 +14,7 @@ import os
 import sys
 import time
 from pathlib import Path
-from typing import Any, Dict, List, Optional
+from typing import Tuple, Any, Dict, List, Optional
 
 REPO_ROOT = Path(__file__).resolve().parent.parent
 for p in [
diff --git a/src/antigravity_provider/router/auto_assigner.py b/src/antigravity_provider/router/auto_assigner.py
index 75d631d..7beb300 100644
--- a/src/antigravity_provider/router/auto_assigner.py
+++ b/src/antigravity_provider/router/auto_assigner.py
@@ -335,7 +335,8 @@ class AutoAssigner:
                 "provider_label": provider_label,
                 "logical_role": log_role,
                 "tier": tier,
-                "is_main": is_main,
+                "is_main": (pid == main_ag and pcfg.provider == "antigravity")
+                or (pid == main_codex and pcfg.provider == "openai-codex"),
                 "identity": ident.primary_identifier() if is_auth else "Не авторизован",
                 "plan": ident.plan.display_name if is_auth else "Тариф: неизвестен",
                 "quota_str": relevant_bucket.formatted_remaining() if relevant_bucket else "Квота: доступна",
diff --git a/src/antigravity_provider/router/hermes_hub_app.py b/src/antigravity_provider/router/hermes_hub_app.py
index c58806b..ef360cf 100644
--- a/src/antigravity_provider/router/hermes_hub_app.py
+++ b/src/antigravity_provider/router/hermes_hub_app.py
@@ -47,7 +47,7 @@ from antigravity_provider.router.adapters import get_adapter
 
 from antigravity_provider.router.ui.theme import Theme
 from antigravity_provider.router.ui.assets import AssetManager
-from antigravity_provider.router.ui.components import HubButton
+from antigravity_provider.router.ui.components import HubButton, HubModal
 from antigravity_provider.router.ui.add_account_wizard import AddAccountWizard
 
 from antigravity_provider.router.unified_health import (
@@ -370,7 +370,7 @@ class HermesHubApp(ctk.CTk):
             except Exception as e:
                 if not self._shutting_down:
                     try:
-                        self.after(0, lambda: self._on_data_error(str(e)))
+                        self.after(0, lambda err=str(e): self._on_data_error(err))
                     except Exception:
                         pass
 
@@ -522,9 +522,9 @@ class HermesHubApp(ctk.CTk):
                 if not self._shutting_down:
                     try:
                         if on_error:
-                            self.after(0, lambda: on_error(str(e)))
+                            self.after(0, lambda err=str(e): on_error(err))
                         else:
-                            self.after(0, lambda: self._show_toast(f"❌ Ошибка: {e}"))
+                            self.after(0, lambda err=str(e): self._show_toast(f"❌ Ошибка: {err}"))
                     except Exception:
                         pass
 
diff --git a/src/antigravity_provider/router/ui/assets.py b/src/antigravity_provider/router/ui/assets.py
index 48a4c9a..6f1d53d 100644
--- a/src/antigravity_provider/router/ui/assets.py
+++ b/src/antigravity_provider/router/ui/assets.py
@@ -3,7 +3,7 @@ from __future__ import annotations
 
 import os
 from pathlib import Path
-from typing import Dict, Optional, Tuple
+from typing import Any, Dict, Optional, Tuple
 
 try:
     from PIL import Image