nisse-review marks a reply that settles its thread; the PR's author resolves it

The reviewer is read-only (R3), so Gitea refuses it resolving a thread.
Now each reply says whether it settles its thread, and a settled reply
carries <!-- nisse-review: settled -->. nisse-dev, as the author, resolves
every comment on that thread's line when it watches the PR, and doesn't
take the settled reply as a point to answer. scripts/resolve_settled.py
does the same for PRs made by hand.

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

@@ -86,6 +86,26 @@ class ReviewNote:
     author: str
     body: str
     where: str  # "path:line" for a line comment, "" for a review body
+    resolved: bool = False  # a line comment's thread, marked resolved
+
+
+# A reviewer's reply that settles its thread: nothing more is needed from
+# it there. It can't resolve the thread itself (read-only, R3), so the PR's
+# author does.
+SETTLED_MARKER = "<!-- nisse-review: settled -->"
+
+
+def to_resolve(notes: list[ReviewNote]) -> list[int]:
+    """The ids of the unresolved line comments in threads a settled reply
+    closed: every comment on that path:line, as Gitea groups a thread."""
+    settled = {
+        n.where for n in notes if n.key.startswith("line-") and SETTLED_MARKER in n.body
+    }
+    return [
+        int(n.key.removeprefix("line-"))
+        for n in notes
+        if n.key.startswith("line-") and n.where in settled and not n.resolved
+    ]
 
 
 @dataclass(frozen=True)
@@ -198,10 +218,16 @@ class GiteaClient:
                         author=(comment.get("user") or {}).get("login", author),
                         body=str(comment.get("body") or ""),
                         where=f"{comment.get('path', '')}:{line}",
+                        resolved=bool(comment.get("resolver")),
                     )
                 )
         return notes
 
+    def resolve_comment(self, repo: str, comment_id: int) -> None:
+        """Mark a line comment's thread resolved: the PR's author or someone
+        with write access may."""
+        self._request("POST", f"/repos/{repo}/pulls/comments/{comment_id}/resolve")
+
     def find_pull_request(self, repo: str, head: str) -> PullRequest | None:
         """External truth for L8: did the PR for this branch already get
         opened? Includes closed PRs — a crash after opening must not be