feat: FollowerConfigManager — unified Global + Override config pattern for followers

Implements the same proven architecture as SafetyManager for follower operational
config: Follower.General defaults → sparse Follower.FollowerOverrides → legacy
per-section fallback (deprecated) → hardcoded fallback. Thread-safe singleton with
O(1) cached lookups and per-param provenance reporting.

Backend changes:
- New FollowerConfigManager singleton (src/classes/follower_config_manager.py)
- 38 unit tests covering resolution hierarchy, caching, provenance, callbacks
- All 8 followers migrated from per-section config reads to FCM calls
- YawRateSmoother adopted in mc_velocity_position + mc_velocity_distance
- config_default.yaml restructured: shared params → Follower.General, sparse
  overrides in Follower.FollowerOverrides, per-follower sections keep unique only
- API endpoints: GET /api/follower/config/general, /api/follower/config/{name}
- Config backend fixes: remove dead deepdiff import, fix restore_backup reload,
  fix revert_to_default _config_raw sync, remove noisy validation warning
- Removed orphaned GimbalTrackerSettings section
- parameters.py: Follower in _GROUPED_SECTIONS, FCM init/reload integration

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

Author: alireza787b

configs/config_default.yaml

@@ -33,7 +33,6 @@
 
 # Use ruamel.yaml for round-trip YAML (comment preservation)
 from ruamel.yaml import YAML
-from deepdiff import DeepDiff
 
 logger = logging.getLogger(__name__)
 
@@ -461,10 +460,8 @@ def validate_value(self, section: str, param: str, value: Any) -> ValidationResu
                         f"Value {value} is above recommended maximum {rec_max}"
                     )
 
-        # Check if value is different from default
-        default_value = self.get_default_parameter(section, param)
-        if value != default_value:
-            warnings.append("Value differs from default")
+        # Note: "differs from default" is informational provenance, not a warning.
+        # The UI can show this via the default_value field in parameter metadata.
 
         # Check reboot requirement
         if param_schema.get('reboot_required', False):
@@ -668,9 +665,15 @@ def revert_to_default(
                 default_section = self.get_default(section)
                 if default_section:
                     self._config[section] = default_section.copy()
+                    # Keep _config_raw in sync for round-trip YAML
+                    if self._config_raw is not None and section in self._config_raw:
+                        for key, value in default_section.items():
+                            self._config_raw[section][key] = value
             else:
                 # Revert everything
                 self._config = self._default.copy()
+                # Reload _config_raw from default file for full round-trip sync
+                self._config_raw = None
 
             logger.info(f"Reverted to default: section={section}, param={param}")
             return True

src/classes/config_service.py

@@ -419,6 +419,10 @@ def define_routes(self):
         self.app.get("/api/safety/limits/{follower_name}")(self.get_follower_safety_limits)
         # Note: /api/safety/vehicle-profiles removed in v4.0.0 (was deprecated in v3.6.0)
 
+        # Follower configuration API endpoints (v6.1.0+)
+        self.app.get("/api/follower/config/general")(self.get_follower_config_general)
+        self.app.get("/api/follower/config/{follower_name}")(self.get_follower_config_effective)
+
         # Enhanced safety/config endpoints (v5.0.0+)
         self.app.get("/api/config/effective-limits")(self.get_effective_limits)
         self.app.get("/api/config/sections/relevant")(self.get_relevant_sections)
@@ -4541,6 +4545,55 @@ def get_group_source(param_names):
 
     # Note: get_vehicle_profiles() removed in v4.0.0 (was deprecated in v3.6.0)
 
+    # ==================== Follower Config API Endpoints (v6.1.0+) ====================
+
+    async def get_follower_config_general(self):
+        """
+        Get Follower.General configuration values.
+
+        Returns:
+            dict: General follower config and available followers with overrides
+        """
+        try:
+            from classes.follower_config_manager import get_follower_config_manager
+            fcm = get_follower_config_manager()
+
+            return JSONResponse(content={
+                'available': True,
+                'general': fcm._general,
+                'follower_overrides': fcm._overrides,
+                'available_followers': fcm.get_available_followers(),
+                'timestamp': time.time()
+            })
+        except Exception as e:
+            self.logger.error(f"Error getting follower config general: {e}")
+            raise HTTPException(status_code=500, detail=str(e))
+
+    async def get_follower_config_effective(self, follower_name: str):
+        """
+        Get per-parameter provenance for a specific follower.
+
+        Args:
+            follower_name: Name of the follower (e.g., 'MC_VELOCITY_CHASE')
+
+        Returns:
+            dict: Per-param effective value, source, override status
+        """
+        try:
+            from classes.follower_config_manager import get_follower_config_manager
+            fcm = get_follower_config_manager()
+
+            summary = fcm.get_effective_config_summary(follower_name)
+
+            return JSONResponse(content={
+                'follower_name': follower_name,
+                'params': summary,
+                'timestamp': time.time()
+            })
+        except Exception as e:
+            self.logger.error(f"Error getting follower config for {follower_name}: {e}")
+            raise HTTPException(status_code=500, detail=str(e))
+
     # ==================== Enhanced Safety/Config API Endpoints (v5.0.0+) ====================
 
     async def get_effective_limits(self, follower_name: str = None):
@@ -4607,8 +4660,8 @@ async def get_relevant_sections(self, follower_mode: str = None):
                 'mc_velocity_distance': ['Follower', 'MC_VELOCITY_DISTANCE', 'Safety', 'PID', 'Tracking', 'OSD'],
                 'mc_velocity_ground': ['Follower', 'MC_VELOCITY_GROUND', 'Safety', 'PID', 'Tracking', 'OSD'],
                 'mc_attitude_rate': ['Follower', 'MC_ATTITUDE_RATE', 'Safety', 'PID', 'Tracking', 'OSD'],
-                'gm_velocity_chase': ['Follower', 'GM_VELOCITY_CHASE', 'Safety', 'GimbalTracker', 'GimbalTrackerSettings', 'PID', 'Tracking', 'Gimbal', 'OSD'],
-                'gm_velocity_vector': ['Follower', 'GM_VELOCITY_VECTOR', 'Safety', 'GimbalTracker', 'GimbalTrackerSettings', 'PID', 'Tracking', 'Gimbal', 'OSD'],
+                'gm_velocity_chase': ['Follower', 'GM_VELOCITY_CHASE', 'Safety', 'GimbalTracker', 'PID', 'Tracking', 'Gimbal', 'OSD'],
+                'gm_velocity_vector': ['Follower', 'GM_VELOCITY_VECTOR', 'Safety', 'GimbalTracker', 'PID', 'Tracking', 'Gimbal', 'OSD'],
                 'fw_attitude_rate': ['Follower', 'FW_ATTITUDE_RATE', 'Safety', 'PID', 'Tracking', 'OSD'],
             }
 
@@ -5471,6 +5524,13 @@ async def restore_config_backup(self, backup_id: str):
             service = self._get_config_service()
             success = service.restore_backup(backup_id)
 
+            # Reload Parameters + managers so runtime reflects the restored config
+            if success:
+                try:
+                    Parameters.reload_config()
+                except Exception as e:
+                    self.logger.error(f"Failed to reload after backup restore: {e}")
+
             return JSONResponse(content={
                 'success': success,
                 'backup_id': backup_id,