feat(plugins): enqueue skill upgrade candidates

app-instance/backend/beaver/memory/skills/store.py

@@ -4,7 +4,12 @@ from __future__ import annotations
 
 import json
 from pathlib import Path
+import threading
 from uuid import uuid4
+from contextlib import contextmanager
+from typing import Iterator
+
+from beaver.foundation.utils.file_lock import WorkspaceWriteLock
 
 from .models import (
     SkillDraftEvalReport,
@@ -16,9 +21,11 @@ from .models import (
 
 
 class SkillLearningStore:
-    def __init__(self, root: str | Path) -> None:
+    def __init__(self, root: str | Path, *, write_lock: WorkspaceWriteLock | None = None) -> None:
         self.root = Path(root)
         self.root.mkdir(parents=True, exist_ok=True)
+        self.write_lock = write_lock
+        self._local_lock = threading.RLock()
         self.performance_path = self.root / "performance.jsonl"
         self.candidates_path = self.root / "learning-candidates.jsonl"
         self.audit_path = self.root / "learning-audit.jsonl"
@@ -26,42 +33,58 @@ class SkillLearningStore:
         self.eval_reports_dir = self.root / "eval-reports"
 
     def record_learning_candidate(self, candidate: SkillLearningCandidate) -> None:
+        self.record_learning_candidate_if_absent(candidate)
+
+    def record_learning_candidate_if_absent(
+        self,
+        candidate: SkillLearningCandidate,
+    ) -> tuple[SkillLearningCandidate, bool]:
         normalized = SkillLearningCandidate.from_dict(candidate.to_dict())
-        self._append_jsonl(self.candidates_path, normalized.to_dict())
-        self.append_audit_event(
-            normalized.candidate_id,
-            "candidate_created",
-            {
-                "kind": normalized.kind,
-                "status": normalized.status,
-                "reason": normalized.reason,
-            },
-        )
+        with self._locked():
+            existing = {
+                item.candidate_id: item
+                for item in self.list_learning_candidates()
+            }
+            found = existing.get(normalized.candidate_id)
+            if found is not None:
+                return found, False
+            self._append_jsonl(self.candidates_path, normalized.to_dict())
+            self.append_audit_event(
+                normalized.candidate_id,
+                "candidate_created",
+                {
+                    "kind": normalized.kind,
+                    "status": normalized.status,
+                    "reason": normalized.reason,
+                },
+            )
+            return normalized, True
 
     def update_learning_candidate(self, candidate_id: str, **updates: object) -> SkillLearningCandidate | None:
-        candidates = self.list_learning_candidates()
-        updated: SkillLearningCandidate | None = None
-        for index, candidate in enumerate(candidates):
-            if candidate.candidate_id != candidate_id:
-                continue
-            payload = candidate.to_dict()
-            payload.update(updates)
-            if "updated_at" not in updates:
-                payload["updated_at"] = _utc_now()
-            updated = SkillLearningCandidate.from_dict(payload)
-            candidates[index] = updated
-            break
-        if updated is None:
-            return None
-        self.candidates_path.parent.mkdir(parents=True, exist_ok=True)
-        self.candidates_path.write_text(
-            "".join(
-                json.dumps(candidate.to_dict(), ensure_ascii=False, sort_keys=True) + "\n"
-                for candidate in candidates
-            ),
-            encoding="utf-8",
-        )
-        return updated
+        with self._locked():
+            candidates = self.list_learning_candidates()
+            updated: SkillLearningCandidate | None = None
+            for index, candidate in enumerate(candidates):
+                if candidate.candidate_id != candidate_id:
+                    continue
+                payload = candidate.to_dict()
+                payload.update(updates)
+                if "updated_at" not in updates:
+                    payload["updated_at"] = _utc_now()
+                updated = SkillLearningCandidate.from_dict(payload)
+                candidates[index] = updated
+                break
+            if updated is None:
+                return None
+            self.candidates_path.parent.mkdir(parents=True, exist_ok=True)
+            self.candidates_path.write_text(
+                "".join(
+                    json.dumps(candidate.to_dict(), ensure_ascii=False, sort_keys=True) + "\n"
+                    for candidate in candidates
+                ),
+                encoding="utf-8",
+            )
+            return updated
 
     def transition_learning_candidate(
         self,
@@ -209,6 +232,15 @@ class SkillLearningStore:
             raise ValueError(f"Expected JSON object in {path}")
         return payload
 
+    @contextmanager
+    def _locked(self) -> Iterator[None]:
+        if self.write_lock is not None:
+            with self.write_lock.acquire(timeout_seconds=10):
+                yield
+            return
+        with self._local_lock:
+            yield
+
 
 def _utc_now() -> str:
     from datetime import datetime, timezone