Fixes from the rest of the live session

- A near miss for abandon ("abort", "cancel", "drop it", ...) in an item's
  thread is asked about, and changes nothing.
- The driver is told only the operator stops or closes an item, so it
  doesn't claim to have done either.
- An issue assigned again after its item closed starts a new item that
  notes the one before (Gitea's timeline gives the assignment time);
  item_for_issue returns the latest item.
- Abandoning an issue Gitea won't close because of open dependencies says
  so, naming them.
- An agreed item isn't offered restate.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PPQ14L3LikyefCMFBqEbKE

nisse-dev/tests/test_gitea.py

@@ -229,3 +229,30 @@ def test_closing_comments_first_then_closes_issue_and_pr() -> None:
         ("POST", "/api/v1/repos/o/r/issues/20/comments", {"body": "abandoned by don"}),
         ("PATCH", "/api/v1/repos/o/r/pulls/20", {"state": "closed"}),
     ]
+
+
+def test_assigned_at_is_the_last_assignment_across_pages() -> None:
+    def assigned(login: str, at: str, removed: bool = False) -> dict:
+        return {
+            "type": "assignees",
+            "assignee": {"login": login},
+            "removed_assignee": removed,
+            "created_at": at,
+        }
+
+    filler = {"type": "comment", "created_at": "t0"}
+    pages = {
+        1: [assigned("dev-agent", "t1")] + [filler] * (PR_PAGE_SIZE - 1),
+        2: [
+            assigned("dev-agent", "t2", removed=True),
+            assigned("someone", "t3"),
+            assigned("dev-agent", "t4"),
+        ],
+    }
+
+    def handler(request: httpx.Request) -> httpx.Response:
+        assert request.url.path == "/api/v1/repos/o/r/issues/6/timeline"
+        return httpx.Response(200, json=pages[int(request.url.params["page"])])
+
+    assert client(handler).assigned_at("o/r", 6, "dev-agent") == "t4"
+    assert client(handler).assigned_at("o/r", 6, "nobody") is None