feat: 人设模板系统、节点调度标签、pydantic-settings收敛、错误处理增强

新增persona_template表和CRUD API，BaseIndividualModel增加node_affinity和template_origin_id字段，
WorkerCluster支持多集群Ray资源调度，环境变量收敛到pydantic-settings统一校验，
数据库异常转换为结构化BusinessError/RetryableError，系统节点支持custom_system_prompt。

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

kilostar/core/postgres_database/module/persona_template.py

@@ -0,0 +1,73 @@
+from sqlalchemy import select
+from ulid import ULID
+
+from kilostar.core.postgres_database.model.persona_template import PersonaTemplate
+from kilostar.core.postgres_database.database_exception import database_exception
+
+
+class PersonaTemplateDatabase:
+    def __init__(self, async_session_maker):
+        self.async_session_maker = async_session_maker
+
+    @database_exception
+    async def add_template(self, **kwargs) -> PersonaTemplate:
+        async with self.async_session_maker() as session:
+            tpl = PersonaTemplate(template_id=str(ULID()), **kwargs)
+            session.add(tpl)
+            await session.commit()
+            await session.refresh(tpl)
+            return tpl
+
+    @database_exception
+    async def get_template(self, template_id: str):
+        async with self.async_session_maker() as session:
+            result = await session.execute(
+                select(PersonaTemplate).where(PersonaTemplate.template_id == template_id)
+            )
+            return result.scalar_one_or_none()
+
+    @database_exception
+    async def list_templates(self, owner_id: str = None, include_builtin: bool = True):
+        async with self.async_session_maker() as session:
+            stmt = select(PersonaTemplate)
+            if owner_id and include_builtin:
+                from sqlalchemy import or_
+                stmt = stmt.where(
+                    or_(PersonaTemplate.owner_id == owner_id, PersonaTemplate.is_builtin == True)
+                )
+            elif owner_id:
+                stmt = stmt.where(PersonaTemplate.owner_id == owner_id)
+            elif include_builtin:
+                stmt = stmt.where(PersonaTemplate.is_builtin == True)
+            result = await session.execute(stmt)
+            return list(result.scalars().all())
+
+    @database_exception
+    async def update_template(self, template_id: str, **kwargs):
+        async with self.async_session_maker() as session:
+            result = await session.execute(
+                select(PersonaTemplate).where(PersonaTemplate.template_id == template_id)
+            )
+            tpl = result.scalar_one_or_none()
+            if not tpl:
+                return None
+            for k, v in kwargs.items():
+                if v is not None:
+                    setattr(tpl, k, v)
+            session.add(tpl)
+            await session.commit()
+            await session.refresh(tpl)
+            return tpl
+
+    @database_exception
+    async def delete_template(self, template_id: str) -> bool:
+        async with self.async_session_maker() as session:
+            result = await session.execute(
+                select(PersonaTemplate).where(PersonaTemplate.template_id == template_id)
+            )
+            tpl = result.scalar_one_or_none()
+            if not tpl:
+                return False
+            await session.delete(tpl)
+            await session.commit()
+            return True