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

docs/Architecture.md

@@ -569,6 +569,9 @@ Work arrives as Gitea issues or conversation, and leaves as reviewed PRs.
   is. The agent acknowledges it ("queued myproject#14, 1 ahead"). Your issue is the
   item's record. Only issues filed or assigned by allowlisted operators count (L11).
 - **Unassigned issues are backlog,** never work, though the agent will discuss them.
+- **An issue assigned again after its item closed is a new item,** which notes the
+  one before it; an issue whose item is still open, or whose assignment predates
+  the close, stays with that item.
 - **Open Gitea dependencies make an issue blocked** (L1).
 - **Work that starts in conversation gets a record** once it is work on a project,
   not at its first message: the transcript already keeps the conversation. The