feat: close issues after merged agent PRs

src/agent_gitea/gitea.py

@@ -23,6 +23,8 @@ class GiteaIssue:
 class GiteaPullRequest:
     number: int
     html_url: str
+    state: str
+    merged: bool
 
 
 @dataclass(frozen=True)
@@ -131,7 +133,12 @@ class GiteaClient:
         )
         response.raise_for_status()
         payload = response.json()
-        return GiteaPullRequest(number=int(payload["number"]), html_url=payload.get("html_url") or "")
+        return pull_request_from_payload(payload)
+
+    def get_pull_request(self, *, owner: str, name: str, pr_number: int) -> GiteaPullRequest:
+        response = self.client.get(f"/repos/{owner}/{name}/pulls/{pr_number}")
+        response.raise_for_status()
+        return pull_request_from_payload(response.json())
 
     def post_issue_comment(self, *, owner: str, name: str, issue_number: int, body: str) -> None:
         response = self.client.post(
@@ -140,6 +147,13 @@ class GiteaClient:
         )
         response.raise_for_status()
 
+    def close_issue(self, *, owner: str, name: str, issue_number: int) -> None:
+        response = self.client.patch(
+            f"/repos/{owner}/{name}/issues/{issue_number}",
+            json={"state": "closed"},
+        )
+        response.raise_for_status()
+
 
 def clone_url_from_repo_payload(payload: dict[str, Any], fallback_base_url: str, owner: str, name: str) -> str:
     return (
@@ -168,3 +182,13 @@ def repository_from_payload(payload: dict[str, Any], fallback_base_url: str) ->
         clone_url=clone_url_from_repo_payload(payload, fallback_base_url, str(owner), str(name)),
         default_branch=payload.get("default_branch") or "main",
     )
+
+
+def pull_request_from_payload(payload: dict[str, Any]) -> GiteaPullRequest:
+    merged = bool(payload.get("merged") or payload.get("has_merged") or payload.get("merged_at"))
+    return GiteaPullRequest(
+        number=int(payload["number"]),
+        html_url=payload.get("html_url") or payload.get("url") or "",
+        state=payload.get("state") or "",
+        merged=merged,
+    )