Add LED skip start/end, rename standby_interval to keepalive_interval, remove migrations

LED skip: set first N and last M LEDs to black on a target. Color sources
(static, gradient, effect, color cycle) render across only the active
(non-skipped) LEDs. Processor pads with blacks before sending to device.

Rename standby_interval → keepalive_interval across all Python, API
schemas, and JS. from_dict falls back to old key for existing configs.

Remove legacy migration functions (_migrate_devices_to_targets,
_migrate_targets_to_color_strips) and legacy fields from target model.

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

server/src/wled_controller/main.py

@@ -54,105 +54,6 @@ processor_manager = ProcessorManager(
 )
 
 
-def _migrate_devices_to_targets():
-    """One-time migration: create picture targets from legacy device settings.
-
-    If the target store is empty and any device has legacy picture_source_id
-    or settings in raw JSON, migrate them to WledPictureTargets.
-    """
-    if picture_target_store.count() > 0:
-        return  # Already have targets, skip migration
-
-    raw = device_store.load_raw()
-    devices_raw = raw.get("devices", {})
-    if not devices_raw:
-        return
-
-    migrated = 0
-    for device_id, device_data in devices_raw.items():
-        legacy_source_id = device_data.get("picture_source_id", "")
-
-        if not legacy_source_id:
-            continue
-
-        device_name = device_data.get("name", device_id)
-        target_name = f"{device_name} Target"
-
-        try:
-            target = picture_target_store.create_target(
-                name=target_name,
-                target_type="wled",
-                device_id=device_id,
-                description=f"Auto-migrated from device {device_name}",
-            )
-            migrated += 1
-            logger.info(f"Migrated device {device_id} -> target {target.id}")
-        except Exception as e:
-            logger.error(f"Failed to migrate device {device_id} to target: {e}")
-
-    if migrated > 0:
-        logger.info(f"Migration complete: created {migrated} picture target(s) from legacy device settings")
-
-
-def _migrate_targets_to_color_strips():
-    """One-time migration: create ColorStripSources from legacy WledPictureTarget data.
-
-    For each WledPictureTarget that has a legacy _legacy_picture_source_id (from old JSON)
-    but no color_strip_source_id, create a ColorStripSource and link it.
-    """
-    from wled_controller.storage.wled_picture_target import WledPictureTarget
-    from wled_controller.core.capture.calibration import create_default_calibration
-
-    migrated = 0
-    for target in picture_target_store.get_all_targets():
-        if not isinstance(target, WledPictureTarget):
-            continue
-        if target.color_strip_source_id:
-            continue  # already migrated
-        if not target._legacy_picture_source_id:
-            continue  # no legacy source to migrate
-
-        legacy_settings = target._legacy_settings or {}
-
-        # Try to get calibration from device (old location)
-        device = device_store.get_device(target.device_id) if target.device_id else None
-        calibration = getattr(device, "_legacy_calibration", None) if device else None
-        if calibration is None:
-            calibration = create_default_calibration(0)
-
-        css_name = f"{target.name} Strip"
-        # Ensure unique name
-        existing_names = {s.name for s in color_strip_store.get_all_sources()}
-        if css_name in existing_names:
-            css_name = f"{target.name} Strip (migrated)"
-
-        try:
-            css = color_strip_store.create_source(
-                name=css_name,
-                source_type="picture",
-                picture_source_id=target._legacy_picture_source_id,
-                fps=legacy_settings.get("fps", 30),
-                brightness=legacy_settings.get("brightness", 1.0),
-                smoothing=legacy_settings.get("smoothing", 0.3),
-                interpolation_mode=legacy_settings.get("interpolation_mode", "average"),
-                calibration=calibration,
-            )
-
-            # Update target to reference the new CSS
-            target.color_strip_source_id = css.id
-            target.standby_interval = legacy_settings.get("standby_interval", 1.0)
-            target.state_check_interval = legacy_settings.get("state_check_interval", 30)
-            picture_target_store._save()
-
-            migrated += 1
-            logger.info(f"Migrated target {target.id} -> CSS {css.id} ({css_name})")
-        except Exception as e:
-            logger.error(f"Failed to migrate target {target.id} to CSS: {e}")
-
-    if migrated > 0:
-        logger.info(f"CSS migration complete: created {migrated} color strip source(s) from legacy targets")
-
-
 @asynccontextmanager
 async def lifespan(app: FastAPI):
     """Application lifespan manager.
@@ -182,10 +83,6 @@ async def lifespan(app: FastAPI):
     logger.info(f"Authorized clients: {client_labels}")
     logger.info("All API requests require valid Bearer token authentication")
 
-    # Run migrations
-    _migrate_devices_to_targets()
-    _migrate_targets_to_color_strips()
-
     # Create profile engine (needs processor_manager)
     profile_engine = ProfileEngine(profile_store, processor_manager)