Close five gaps the loop model found

- abandon closes the item's open PRs
- a PR the operator closed is an answer, never reopened by a retry
- a review fix for a PR that merged meanwhile goes out as a new PR
- redoing a milestone after a closed PR gets a new branch and PR
- a record issue carries its work item's ID from creation

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

docs/Architecture.md

@@ -199,8 +199,8 @@ again after a restart), permissions (L3), and work in progress as intents (L8).
   else is a bug, which the model checker (`specs/`) guards against.
 - **`stop` works in every state:** it ends the current turn or delegation at the
   next tool boundary, unmounts elevated credentials, and asks what next.
-- **`abandon` ends a work item** from any waiting point, closing its record with a
-  note and aborting its unresolved intents.
+- **`abandon` ends a work item** from any waiting point, closing its record and
+  any open PRs with a note and aborting its unresolved intents.
 - **Every action passes through the three layers** (P4).
 
 ### L3. Authority: scope and approvals
@@ -379,7 +379,8 @@ migration hook.
 - **Before any external side effect, record an intent;** after it, commit it.
 - **Every external effect is idempotent against external truth:** re-running an
   interrupted step detects and adopts what already happened (e.g. an open PR for
-  the branch).
+  the branch). What the operator has since undone is an answer, not a gap to
+  fill: a PR they closed is reported, never opened again.
 - **Intake is taken at most once and answered at least once:** a durable cursor per
   external thread; an item being answered stays marked until done and is
   redelivered after a crash; comments the agent can't act on yet aren't consumed.
@@ -397,8 +398,9 @@ migration hook.
    out and its approval hasn't expired (O2); anything else is reported with what is
    known, and the operator chooses. Never a blind resume.
 
-**Verification:** these rules are checked by a formal model (`specs/`, Quint) over
-interleavings of messages, comments, outcomes and crashes. Each counterexample is
+**Verification:** these rules, and the loop's (L1, L2, D1, D4, D5), are checked by
+formal models (`specs/`, Quint) over interleavings of messages, comments, outcomes
+and crashes. Each counterexample is
 reproduced against the real code before it is fixed.
 
 ### L9. Models, roles and helpers
@@ -551,8 +553,10 @@ Work arrives as Gitea issues or conversation, and leaves as reviewed PRs.
 - **Unassigned issues are backlog,** never work, though the agent will discuss them.
 - **Open Gitea dependencies make an issue blocked** (L1).
 - **Work that starts in conversation gets a record:** the agent opens an issue,
-  assigned to itself and linked to the item. Intake ignores issues already linked,
-  so nothing is picked up twice. This is the only time the agent assigns itself.
+  assigned to itself, that carries the work item's ID from the moment it is
+  created. Intake ignores any issue carrying an ID, so a record is never taken for
+  new work, even before the agent has stored the link. This is the only time the
+  agent assigns itself.
 
 **Starting an item.** The agent reads the project's documents (D2), then
 **restates its understanding** in the item's thread: what it takes the request to
@@ -654,7 +658,8 @@ Installing on any other host is class 3.
   branch only after the previous PR has merged (read from Gitea). Meanwhile the item
   waits on the operator and the agent does other work. A review comment makes the
   item ready (D5); a PR closed without merging makes it ready with that fact, and the
-  agent asks what next.
+  agent asks what next. Redoing the milestone gets a new branch and PR, and the
+  merge rule still applies to it.
 - **Parking pushes the item's branch,** so another item on the same project starts
   fresh and this one resumes from its branch.
 - **Publish only the work:** what the agent changed, counted from where the
@@ -677,6 +682,9 @@ Installing on any other host is class 3.
 - **Operator comments on a PR** (conversation and inline) are instructions; the
   agent answers with commits to the same PR, replying where the comment was made.
   Intake is as in L8.
+- **The PR may have moved on meanwhile.** After pushing a fix, the agent checks the
+  PR: if it merged before the fix landed, the fix goes out as a new PR; if it was
+  closed, the agent says so and asks.
 - **Merging follows the trust dial** (L3). Today the operator merges. If the dial
   lets the agent merge its own PRs once checks pass, branch protection must require
   an approval the agent's account can't give, so Gitea enforces the rule.