chore: remainder — backend test infra, agent config, docker, i18n, frontend ui

- Backend: alembic env, config manager/models, dependencies, translate plugin
- Backend tests: async_sync_regression, integration tests, git services, test_agent
- Docker: docker-compose.yml updates
- Agent: qa-tester.md update, semantics-testing SKILL.md update
- Frontend: TopNavbar, sidebarNavigation, FeaturesSettings, FeatureGate
- i18n: assistant.json en/ru locale updates
- New: frontend/src/lib/components/agent/ directory

backend/src/core/config_manager.py

@@ -146,25 +146,22 @@ class ConfigManager:
     # @PURPOSE: Read FEATURES__* env vars and apply them to a GlobalSettings features config.
     # @SIDE_EFFECT  Reads os.environ; mutates settings.features in-place.
     # @RATIONALE  Env vars seed the initial defaults. After first bootstrap, DB is source of truth.
+    # @INVARIANT All FeaturesConfig fields can be overridden via FEATURES__<FIELD_NAME> env vars.
     @staticmethod
     def _apply_features_from_env(settings: GlobalSettings) -> None:
         with belief_scope("ConfigManager._apply_features_from_env"):
-            dataset_review_env = os.getenv("FEATURES__DATASET_REVIEW")
-            if dataset_review_env is not None:
-                parsed = dataset_review_env.strip().lower() in ("true", "1", "yes")
-                settings.features.dataset_review = parsed
-                logger.reason(
-                    "Applied FEATURES__DATASET_REVIEW from env",
-                    extra={"value": parsed, "raw": dataset_review_env},
-                )
-            health_monitor_env = os.getenv("FEATURES__HEALTH_MONITOR")
-            if health_monitor_env is not None:
-                parsed = health_monitor_env.strip().lower() in ("true", "1", "yes")
-                settings.features.health_monitor = parsed
-                logger.reason(
-                    "Applied FEATURES__HEALTH_MONITOR from env",
-                    extra={"value": parsed, "raw": health_monitor_env},
-                )
+            # Dynamically apply FEATURES__* env vars to all FeaturesConfig fields
+            features_prefix = "FEATURES__"
+            for field_name in type(settings.features).model_fields:
+                env_key = f"{features_prefix}{field_name.upper()}"
+                env_value = os.getenv(env_key)
+                if env_value is not None:
+                    parsed = env_value.strip().lower() in ("true", "1", "yes")
+                    setattr(settings.features, field_name, parsed)
+                    logger.reason(
+                        f"Applied {env_key} from env",
+                        extra={"value": parsed, "raw": env_value},
+                    )
 
             app_timezone_env = os.getenv("APP_TIMEZONE")
             if app_timezone_env is not None:

backend/src/core/config_models.py

@@ -141,10 +141,34 @@ class CleanReleaseConfig(BaseModel):
 # @BRIEF Top-level feature flags that toggle entire project features on/off.
 # @RATIONALE  Features are read from environment variables on bootstrap and persisted in DB.
 #            DB is source of truth after initial bootstrap; env vars only seed defaults.
+# @INVARIANT Each feature flag controls visibility of plugin/service in UI and API access.
 class FeaturesConfig(BaseModel):
+    # ── Core Features ────────────────────────────────────────
     dataset_review: bool = True
     health_monitor: bool = True
 
+    # ── Plugin Features ──────────────────────────────────────
+    # Translation subsystem
+    translate: bool = True                    # LLM Table Translation (main)
+    translate_scheduling: bool = True          # Cron-based translation scheduling
+    translate_dictionaries: bool = True        # Terminology dictionary management
+
+    # Dashboard migration & version control
+    migration: bool = True                    # Superset Dashboard Migration
+    git_integration: bool = True              # Git Integration
+
+    # System tools
+    backup: bool = True                       # Superset Dashboard Backup
+    debug: bool = True                        # System Diagnostics
+    storage_manager: bool = True              # Storage Manager
+    dataset_mapper: bool = True               # Dataset Column Mapper
+    search_datasets: bool = True              # Search Datasets
+    maintenance_banner: bool = True           # Maintenance Banner
+
+    # LLM analysis tools
+    llm_dashboard_validation: bool = True     # Dashboard LLM Validation
+    llm_documentation: bool = True            # Dataset LLM Documentation
+
 
 # #endregion FeaturesConfig