M7.3: nisse-review's first slice

A new package over nisse-core: it reviews every ready PR in the
repositories its account can read, and posts one COMMENT review.

- scheduler: each round, open PRs per readable repository (or the
  configured repositories); an item per PR, ready unless draft or WIP;
  closed with the PR. One review at a time, oldest first.
- reader: the repository at head and base from Gitea archives, unpacked
  and read in Python (read_file, list_files, search_code), and its issues;
  bound to the item's repository; no git, no shell.
- review: starts from the PR, commits, diff, comments, closed issues, CI;
  comment drafts a point on any existing line; post_review posts one
  COMMENT review at the head, inline where Gitea takes it, else as links in
  the summary. ask_expert; vault and memory (memory/nisse-review).
- L8: posting is an intent; recovery asks Gitea for the marked review and
  never posts twice; with Gitea down, the item waits.
- Failures retried, then said on the PR until the next push.
- Startup refuses an account that can push to or administer any repo.
- nisse-core gitea: readable_repositories, open_pull_requests, diff,
  commits, archive, issue, search_issues, reviews, post_review; PR fields.
- Bring-up: scripts/review-bringup.sh; nisse-review.example.yaml.
- Tests: unit over a fake Gitea and scripted model; a live test
  (NISSE_REVIEW_GITEA_TOKEN) reviews a PR in a fresh test repository.
- Docs: Development Plan M7.3, Tuning Guide (tuning.review.*).

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01J5Utyfzw7gF7UhjRDEtjTk

nisse-core/src/nisse_core/gitea.py

@@ -11,6 +11,7 @@ effect already happened rather than repeating it.
 """
 
 import base64
+from collections.abc import Sequence
 from dataclasses import dataclass
 from typing import Any
 
@@ -36,6 +37,30 @@ class PullRequest:
     merged: bool = False
     head_sha: str = ""  # the commit the PR is at now
     mergeable: bool | None = None  # None: Gitea didn't say
+    title: str = ""
+    body: str = ""
+    author: str = ""
+    base: str = ""  # the branch it would merge into
+    draft: bool = False
+
+
+@dataclass(frozen=True)
+class Review:
+    id: int
+    author: str
+    state: str  # COMMENT, APPROVED, REQUEST_CHANGES, ...
+    commit: str  # the commit it reviewed
+    body: str
+
+
+@dataclass(frozen=True)
+class LineComment:
+    """A review comment on one line of a file, as posted: ``line`` in the
+    file at the PR's head."""
+
+    path: str
+    line: int
+    body: str
 
 
 @dataclass(frozen=True)
@@ -104,6 +129,19 @@ class GiteaClient:
             )
         return response.json() if response.content else None
 
+    def _raw(self, path: str, **kwargs: Any) -> bytes:
+        """A GET whose answer isn't JSON: a diff, an archive."""
+        try:
+            response = self._http.get(path, **kwargs)
+        except httpx.HTTPError as exc:
+            raise GiteaError(f"gitea request failed: {exc}") from exc
+        if response.status_code >= 400:
+            raise GiteaError(
+                f"gitea GET {path} returned {response.status_code}: "
+                f"{response.text[:300]}"
+            )
+        return response.content
+
     def ssh_url(self, repo: str) -> str:
         """The repository's SSH clone URL, which carries no credential."""
         return str(self._request("GET", f"/repos/{repo}")["ssh_url"])
@@ -363,10 +401,118 @@ class GiteaClient:
             "PATCH", f"/repos/{repo}/issues/{index}", json={"state": "closed"}
         )
 
+    def readable_repositories(self) -> list[str]:
+        """Every repository this account can read, as "owner/name"."""
+        found: list[str] = []
+        for page in range(1, MAX_PR_PAGES + 1):
+            items = (
+                self._request(
+                    "GET", "/user/repos", params={"limit": PR_PAGE_SIZE, "page": page}
+                )
+                or []
+            )
+            found += [str(item["full_name"]) for item in items]
+            if len(items) < PR_PAGE_SIZE:
+                return found
+        raise GiteaError("too many repositories to list")
+
+    def open_pull_requests(self, repo: str) -> list[PullRequest]:
+        found: list[PullRequest] = []
+        for page in range(1, MAX_PR_PAGES + 1):
+            items = (
+                self._request(
+                    "GET",
+                    f"/repos/{repo}/pulls",
+                    params={"state": "open", "limit": PR_PAGE_SIZE, "page": page},
+                )
+                or []
+            )
+            found += [_pull_request(item) for item in items]
+            if len(items) < PR_PAGE_SIZE:
+                return found
+        raise GiteaError(f"too many open pull requests in {repo} to list")
+
+    def pull_request_diff(self, repo: str, index: int) -> str:
+        return self._raw(f"/repos/{repo}/pulls/{index}.diff").decode("utf-8", "replace")
+
+    def pull_request_commits(self, repo: str, index: int) -> list[str]:
+        """The PR's commits, oldest first, as "sha7 first line"."""
+        items = self._request("GET", f"/repos/{repo}/pulls/{index}/commits") or []
+        found = []
+        for item in items:
+            message = str((item.get("commit") or {}).get("message") or "")
+            first = message.splitlines()[0] if message.strip() else ""
+            found.append(f"{str(item.get('sha', ''))[:7]} {first}".strip())
+        return found
+
+    def archive(self, repo: str, ref: str) -> bytes:
+        """The repository at ``ref`` (a commit or branch), as a .tar.gz."""
+        return self._raw(f"/repos/{repo}/archive/{ref}.tar.gz")
+
+    def issue(self, repo: str, index: int) -> Issue:
+        return _issue(self._request("GET", f"/repos/{repo}/issues/{index}"))
+
+    def search_issues(self, repo: str, text: str) -> list[Issue]:
+        """Issues (not PRs), open or closed, whose text matches."""
+        items = self._request(
+            "GET",
+            f"/repos/{repo}/issues",
+            params={"q": text, "type": "issues", "state": "all", "limit": 20},
+        )
+        return [_issue(item) for item in items or []]
+
+    def reviews(self, repo: str, index: int) -> list[Review]:
+        return [
+            Review(
+                id=int(item["id"]),
+                author=(item.get("user") or {}).get("login", ""),
+                state=str(item.get("state") or ""),
+                commit=str(item.get("commit_id") or ""),
+                body=str(item.get("body") or ""),
+            )
+            for item in self._request("GET", f"/repos/{repo}/pulls/{index}/reviews")
+            or []
+        ]
+
+    def post_review(
+        self,
+        repo: str,
+        index: int,
+        *,
+        body: str,
+        commit: str,
+        comments: Sequence[LineComment] = (),
+    ) -> int:
+        """A COMMENT review: never an approval or a request for changes."""
+        data = self._request(
+            "POST",
+            f"/repos/{repo}/pulls/{index}/reviews",
+            json={
+                "event": "COMMENT",
+                "body": body,
+                "commit_id": commit,
+                "comments": [
+                    {"path": c.path, "new_position": c.line, "body": c.body}
+                    for c in comments
+                ],
+            },
+        )
+        return int(data["id"])
+
     def close(self) -> None:
         self._http.close()
 
 
+def _issue(item: dict[str, Any]) -> Issue:
+    return Issue(
+        number=int(item["number"]),
+        title=str(item.get("title") or ""),
+        body=str(item.get("body") or ""),
+        author=str((item.get("user") or {}).get("login", "")),
+        labels=tuple(str(label["name"]) for label in item.get("labels") or []),
+    )
+
+
 def _pull_request(data: dict[str, Any]) -> PullRequest:
     return PullRequest(
         number=data["number"],
@@ -376,6 +522,11 @@ def _pull_request(data: dict[str, Any]) -> PullRequest:
         merged=bool(data.get("merged")),
         head_sha=(data.get("head") or {}).get("sha", ""),
         mergeable=data.get("mergeable"),
+        title=str(data.get("title") or ""),
+        body=str(data.get("body") or ""),
+        author=str((data.get("user") or {}).get("login", "")),
+        base=str((data.get("base") or {}).get("ref", "")),
+        draft=bool(data.get("draft")),
     )