fix(sdlc): 目录层 essential 基础规范优先排序——project-directory-spec 等 essential 技能排最前，不被 60 个截断

pipeline_service/agent_loop.py

@@ -1026,7 +1026,8 @@ async def _build_role_skills_block(sor, project_id, role, org_id=""):
         if not merged:
             return ""
         skills = sorted(merged.values(),
-                        key=lambda s: -SCOPE_PRIORITY.get(getattr(s, 'scope', ''), 0))
+                        key=lambda s: (-int(getattr(s, 'essential', False)),
+                                       -SCOPE_PRIORITY.get(getattr(s, 'scope', ''), 0)))
         lines = ["## 可用技能（目录，按需用 load_skill 加载全文；优先级 角色>项目>产线>组织>通用）"]
         for s in skills[:60]:
             tag = SCOPE_TAG.get(getattr(s, 'scope', ''), getattr(s, 'scope', ''))