feat(app): 移除内置agents并添加CORS支持和技能上传优化

移除了agents/registry.json中的所有内置agents配置，将agents数组清空。
为web应用添加了CORS中间件支持，允许指定的前端地址跨域访问。
重构了技能上传功能，增加了LLM重写机制，自动规范化上传的技能格式。
新增了工具名称提取逻辑，从技能正文中自动识别Required Tools段落。
更新了技能学习候选者和草稿的载荷结构，添加评估报告统计信息。
修改了意图路由技能的说明，改进任务状态管理逻辑。

app-instance/backend/beaver/skills/learning/synthesizer.py

@@ -6,6 +6,7 @@ import json
 from typing import Any
 
 from beaver.engine.providers.base import LLMProvider
+from beaver.skills.authoring import canonical_skill_format_instructions, ensure_canonical_skill_body, normalize_skill_frontmatter
 from beaver.skills.learning.evidence import EvidencePacket
 from beaver.memory.skills.models import SkillLearningCandidate
 
@@ -58,7 +59,8 @@ class SkillDraftSynthesizer:
                     "content": (
                         "You synthesize Beaver skill drafts from execution evidence. "
                         "Return only JSON with keys: frontmatter, content, change_reason, "
-                        "preserved_sections, changed_sections, dropped_sections."
+                        "preserved_sections, changed_sections, dropped_sections. "
+                        "The content must follow the Canonical Beaver SKILL.md format."
                     ),
                 },
                 {"role": "user", "content": prompt},
@@ -113,6 +115,7 @@ class SkillDraftSynthesizer:
             + "\n- tools: an explicit JSON array of exact tool names this skill needs. "
             + "Prefer called tool names when the workflow depends on them; use run-selected tool names only when clearly required. "
             + "Use [] only when no tool is required."
+            + "\n\n" + canonical_skill_format_instructions()
             + "\nThe JSON may include preserved_sections, changed_sections, and dropped_sections arrays."
         )
 
@@ -144,14 +147,23 @@ class SkillDraftSynthesizer:
 
     @staticmethod
     def _normalize_payload(payload: dict[str, Any], evidence_packet: EvidencePacket) -> dict[str, Any]:
-        frontmatter = dict(payload.get("frontmatter") or {})
+        frontmatter = normalize_skill_frontmatter(
+            dict(payload.get("frontmatter") or {}),
+            skill_name=str((payload.get("frontmatter") or {}).get("name") or "generated-skill"),
+        )
         tool_hints = _coerce_string_list(frontmatter.get("tools"))
         if not tool_hints:
             tool_hints = _coerce_string_list(evidence_packet.metadata.get("tool_names"))
         frontmatter["tools"] = tool_hints
+        content = ensure_canonical_skill_body(
+            str(payload.get("content") or "").strip(),
+            title=str(frontmatter.get("name") or "generated-skill"),
+            description=str(frontmatter.get("description") or ""),
+            tools=tool_hints,
+        )
         return {
             "frontmatter": frontmatter,
-            "content": str(payload.get("content") or "").strip(),
+            "content": content,
             "change_reason": str(payload.get("change_reason") or ""),
             "preserved_sections": _coerce_string_list(payload.get("preserved_sections")),
             "changed_sections": _coerce_string_list(payload.get("changed_sections")),
@@ -162,13 +174,20 @@ class SkillDraftSynthesizer:
     def _fallback_payload(candidate: SkillLearningCandidate, evidence_packet: EvidencePacket, action: str) -> dict[str, Any]:
         related = candidate.related_skill_names[0] if candidate.related_skill_names else "generated-skill"
         title = related.replace("_", "-")
-        content = "\n".join(f"- {item}" for item in evidence_packet.task_summaries[:5]) or "- No evidence captured."
+        tools = _coerce_string_list(evidence_packet.metadata.get("tool_names"))
+        content = ensure_canonical_skill_body(
+            "\n".join(f"- {item}" for item in evidence_packet.task_summaries[:5]) or "- No evidence captured.",
+            title=title,
+            description=candidate.reason or f"Auto-generated {action} draft for {title}.",
+            tools=tools,
+        )
         return {
             "frontmatter": {
+                "name": title,
                 "description": candidate.reason or f"Auto-generated {action} draft for {title}.",
-                "tools": _coerce_string_list(evidence_packet.metadata.get("tool_names")),
+                "tools": tools,
             },
-            "content": f"# {title}\n\n## Evidence\n\n{content}\n",
+            "content": content,
             "change_reason": candidate.reason or f"Fallback {action} synthesis.",
             "preserved_sections": [],
             "changed_sections": [],