feat: add seat-scoped static and dynamic assistant modes

config/scene_templates/seat_dynamic.yaml

@@ -0,0 +1,23 @@
+id: seat-dynamic
+name: 座椅动态舒缓模式
+aliases: [座椅动态模式, 座椅的动态模式, 动态座椅模式, 座椅循环模式, 座椅交替放松模式, 动态放松模式]
+description: 驻车使用的有界双座舒缓时间轴；主驾在放松和舒缓按摩间切换，副驾靠背与腿托小幅交替，30秒一个阶段、重复5次，总计5分钟。不自动移动主驾位置；停止后不再进入后续阶段。
+icon: activity
+schedule:
+  schema: cognitive-agent-mode-schedule/v1
+  repeat_count: 5
+  phases:
+    - id: relax
+      name: 舒展支撑
+      duration_ms: 30000
+      operations:
+        - {domain: seat, capability: seat.set_driver_massage_native, target_scope: driver, operation: set, parameters: {action: mode, mode: relax}, reason: 主驾使用原生放松按摩，不改变驾驶姿态。}
+        - {domain: seat, capability: seat.set_backrest_recline, target_scope: passenger, operation: set, parameters: {position_pct: 45}, reason: 驻车时副驾适度舒展。}
+        - {domain: seat, capability: seat.set_legrest_height, target_scope: passenger, operation: set, parameters: {position_pct: 25}, reason: 适度支撑腿部。}
+    - id: support
+      name: 轻柔回落
+      duration_ms: 30000
+      operations:
+        - {domain: seat, capability: seat.set_driver_massage_native, target_scope: driver, operation: set, parameters: {action: mode, mode: slack}, reason: 主驾切换舒缓按摩。}
+        - {domain: seat, capability: seat.set_backrest_recline, target_scope: passenger, operation: set, parameters: {position_pct: 40}, reason: 副驾小幅回到支撑姿态。}
+        - {domain: seat, capability: seat.set_legrest_height, target_scope: passenger, operation: set, parameters: {position_pct: 20}, reason: 腿托小幅回落，不使用无界轴运动。}