refactor(log): separate logging into GitHubLogger

Decouple logging from GitHubPRAgent. Introduce logger/github_logger.py for appending JSONL logs to a dedicated repo/branch/file via env config. Wire workflow to use the new logger.

agent/workflow.py

@@ -204,11 +204,12 @@ def generate_github_pr(
             else:
                 toctree_status = f"\n📋 **Toctree Update Failed:** ❌ {toctree_result['message']}"
 
-        # Append full result JSON to GitHub log file (always, env-configured repo/branch/path)
+        # Append full result JSON to dedicated GitHub logging repository (always)
         try:
             import json
+            from logger.github_logger import GitHubLogger
             log_entry = json.dumps(result, ensure_ascii=False) + "\n"
-            log_res = agent.append_to_log_file(log_entry=log_entry)
+            log_res = GitHubLogger().append_jsonl(log_entry)
             print(f"📝 Log append result: {log_res}")
         except Exception as e:
             print(f"❌ Failed to append PR log via GitHub API: {e}")

logger/github_logger.py

@@ -0,0 +1,75 @@
+import os
+import base64
+from typing import Optional
+
+try:
+    from github import Github, GithubException
+    LIBS_OK = True
+except ImportError:
+    LIBS_OK = False
+
+class GitHubLogger:
+    """Dedicated logger that appends JSONL entries to a GitHub repo/branch/file.
+
+    Env vars:
+      - LOG_GITHUB_TOKEN (fallback: GITHUB_TOKEN)
+      - LOG_REPO or LOG_REPO_OWNER + LOG_REPO_NAME
+      - LOG_BRANCH (default: 'log_event')
+      - LOG_FILE_PATH (default: 'pr_success.log')
+    """
+
+    def __init__(self):
+        if not LIBS_OK:
+            raise ImportError("PyGithub not installed. Please install PyGithub.")
+        token = os.environ.get("LOG_GITHUB_TOKEN") or os.environ.get("GITHUB_TOKEN")
+        if not token:
+            raise ValueError("Missing LOG_GITHUB_TOKEN or GITHUB_TOKEN for logging")
+        self._client = Github(token)
+
+        repo_spec = os.environ.get("LOG_REPO")
+        if repo_spec and "/" in repo_spec:
+            self.owner, self.repo_name = repo_spec.split("/", 1)
+        else:
+            self.owner = os.environ.get("LOG_REPO_OWNER")
+            self.repo_name = os.environ.get("LOG_REPO_NAME")
+        if not self.owner or not self.repo_name:
+            raise ValueError("Missing LOG_REPO or LOG_REPO_OWNER/LOG_REPO_NAME")
+
+        self.branch = os.environ.get("LOG_BRANCH", "log_event")
+        self.path = os.environ.get("LOG_FILE_PATH", "pr_success.log")
+
+    def _ensure_branch(self, repo):
+        try:
+            repo.get_branch(self.branch)
+        except GithubException as e:
+            if e.status == 404:
+                base = repo.get_branch(repo.default_branch)
+                repo.create_git_ref(ref=f"refs/heads/{self.branch}", sha=base.commit.sha)
+            else:
+                raise
+
+    def append_jsonl(self, jsonl_line: str, commit_message: str = "chore(log): append entry") -> str:
+        repo = self._client.get_repo(f"{self.owner}/{self.repo_name}")
+        self._ensure_branch(repo)
+        try:
+            existing = repo.get_contents(self.path, ref=self.branch)
+            existing_content = base64.b64decode(existing.content).decode("utf-8")
+            new_content = existing_content + jsonl_line
+            repo.update_file(
+                path=self.path,
+                message=commit_message,
+                content=new_content,
+                sha=existing.sha,
+                branch=self.branch,
+            )
+            return "SUCCESS: Log appended"
+        except GithubException as e:
+            if e.status == 404:
+                repo.create_file(
+                    path=self.path,
+                    message=commit_message,
+                    content=jsonl_line,
+                    branch=self.branch,
+                )
+                return "SUCCESS: Log file created and first entry appended"
+            raise