Wire delegation to A12's trigger, and implement A3's resume rule

Two gaps found by auditing spec against code, the second created by
7b landing the harness without its boot-time half.

**The harness was not connected to anything.** Only a live test
constructed a Delegation; A12's failure-count trigger still gated to
the human, which A13 describes as the fallback rather than the path.
Consecutive command failures now hand the sub-task to the delegate,
with the failures in the brief so it need not rediscover what the
local model learned the hard way. A usable handback lets the local
loop carry on; anything else escalates, because a cap breach leaves a
half-edited tree.

**A3 step 5 was unimplemented.** A crash mid-delegation failed safe —
boot gated on "restarted mid-EXECUTING" — but always gated, even on
the clean cut the spec says should resume, and left the branch orphaned
because _abandon only runs while the process lives.

- A delegation now records an intent before the branch exists, and
  settles it whichever way the delegation ends; an aborted delegation
  is a finished one, and leaving it pending would make the next boot
  believe work was still in flight
- delegation_verdict implements the clean-cut test as an observable
  check, never model self-assessment: settled if a completion follows
  the start, absent if the branch was never created, gate on a
  tool_call with no recorded result, resume otherwise
- recover() sweeps at boot, announcing a resume with a notice rather
  than a question, since a clean cut needs no decision from the
  operator, and leaving an unclean one pending so the generic sweep
  gates on it
- resume() continues the same delegation rather than starting a
  second: no new branch, no second delegation_started, because A10
  defines a session as the delegation, not the process lifetime

Honest limit, stated in the code: "the branch sits at the expected
commit" is approximated by the branch existing and carrying the work,
since per-turn shas are not recorded in the log, so a branch rewritten
underneath us would go undetected.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

nisse-dev/src/nisse_dev/delegation.py

@@ -37,7 +37,8 @@ from nisse_dev.canonical import (
 )
 from nisse_dev.git import GitError, GitRepo
 from nisse_dev.llm import LLMClient, LLMError
-from nisse_dev.state import StateStore
+from nisse_dev.reconcile import Reconciler
+from nisse_dev.state import Intent, StateStore
 from nisse_dev.tools import EXECUTOR_TOOLS, MUTATING_TOOLS, Workspace
 
 DELEGATION_INTENT = "delegation"
@@ -169,6 +170,19 @@ class Delegation:
     ) -> DelegationResult:
         started_at = self._now()
         base_branch = self._git.current_branch()
+        # Recorded before the branch exists, so a crash anywhere after this
+        # leaves a durable statement of what was in flight (A2/A3).
+        intent_id = self._store.begin_intent(
+            DELEGATION_INTENT,
+            {
+                "branch": branch,
+                "base": base_branch,
+                "brief": brief,
+                "role": role,
+                "caps": self._caps.as_payload(),
+            },
+            cause=f"delegating to {self._model}",
+        )
         try:
             # Commit whatever the caller had in flight onto their own branch
             # first. Otherwise it would ride along onto the delegation branch
@@ -176,6 +190,7 @@ class Delegation:
             self._git.commit_all("Checkpoint before delegating")
             self._git.checkout_new_branch(branch)
         except GitError as exc:
+            self._store.abort_intent(intent_id, cause=f"could not branch: {exc}")
             return DelegationResult("failed", f"could not branch for delegation: {exc}")
 
         self._store.append_event(
@@ -201,8 +216,77 @@ class Delegation:
             # Abort discards the branch: the caller must never resume on top
             # of a partially-edited tree (A13).
             self._abandon(branch, base_branch)
+        # Settled either way: an aborted delegation is a *finished* one, and
+        # leaving the intent pending would make the next boot think work was
+        # still in flight.
+        self._store.commit_intent(intent_id, cause=f"delegation {result.status}")
         return result
 
+    def resume(self, intent: Intent) -> DelegationResult:
+        """Continue a delegation the process died in the middle of (A3 step 5).
+
+        The transcript is already in the canonical log, so the loop re-renders
+        it and carries on. No new branch and no second ``delegation_started``:
+        this is the same delegation, which is why its vendor-opaque reasoning
+        may still be replayed (A10 defines a session as the delegation, not the
+        process lifetime).
+        """
+        payload = intent.payload
+        branch = str(payload["branch"])
+        started_at = self._now()
+        try:
+            self._git.checkout_existing_branch(branch)
+        except GitError as exc:
+            self._store.commit_intent(
+                intent.id, cause=f"delegation branch unusable: {exc}"
+            )
+            return DelegationResult("failed", f"could not resume on {branch}: {exc}")
+
+        result = self._loop(str(payload.get("brief", "")), branch, started_at)
+        result.duration_s = self._now() - started_at
+        self._store.append_event(
+            DelegationCompleted(
+                handback=result.handback.render() if result.handback else result.note,
+                artifacts=result.artifacts,
+                tokens=result.tokens,
+                duration_s=result.duration_s,
+                exit_status=result.status,
+            )
+        )
+        if not result.usable:
+            self._abandon(branch, str(payload.get("base", "main")))
+        self._store.commit_intent(intent.id, cause=f"delegation {result.status}")
+        return result
+
+    def recover(self, notify: Callable[[str], None]) -> DelegationResult | None:
+        """Sweep pending delegation intents at boot (A3 step 5).
+
+        Settles what is already finished, discards what never started, resumes
+        a clean cut — announcing it with a *notice*, not a question, because a
+        clean cut needs no decision from the operator — and leaves an unclean
+        one pending so the generic boot sweep gates on it.
+        """
+        for intent in self._store.pending_intents():
+            if intent.kind != DELEGATION_INTENT:
+                continue
+            verdict = delegation_verdict(self._store, self._git, intent)
+            branch = intent.payload.get("branch")
+            if verdict == "settled":
+                self._store.commit_intent(
+                    intent.id, cause="delegation had already completed"
+                )
+            elif verdict == "absent":
+                self._store.abort_intent(
+                    intent.id, cause=f"delegation branch {branch} never created"
+                )
+            elif verdict == "resume":
+                notify(
+                    f"resuming the delegation interrupted on {branch}; "
+                    "the transcript and branch are intact"
+                )
+                return self.resume(intent)
+        return None
+
     def _loop(self, brief: str, branch: str, started_at: float) -> DelegationResult:
         system = (
             f"{SYSTEM_PROMPT}\n\n{self._workspace.describe()}"
@@ -361,3 +445,64 @@ def _parse_handback(arguments: dict[str, Any]) -> Handback | None:
         next=str(arguments["next"]).strip(),
         succeeded=succeeded,
     )
+
+
+def delegation_reconciler(store: StateStore, git_repo: GitRepo) -> Reconciler:
+    """A3 step 5: decide whether an interrupted delegation may be resumed.
+
+    The judgement is an observable check, never model self-assessment — the
+    same reasoning as A12. Returns:
+
+    - ``True``  the delegation is settled or cleanly resumable
+    - ``False`` it never really started, so there is nothing to resume
+    - ``None``  the cut is unclean, so boot gates to the operator
+
+    "The branch sits at the expected commit" is approximated by the branch
+    existing and carrying the delegation's commits: per-turn shas are not
+    recorded in the log today, so a branch rewritten out from under us would
+    not be detected. Stated rather than glossed, because the check is weaker
+    than A3's wording implies.
+    """
+
+    def check(intent: Intent) -> bool | None:
+        verdict = delegation_verdict(store, git_repo, intent)
+        if verdict in ("resume", "settled"):
+            return True
+        return False if verdict == "absent" else None
+
+    return check
+
+
+def delegation_verdict(
+    store: StateStore, git_repo: GitRepo, intent: Intent
+) -> Literal["resume", "settled", "absent", "gate"]:
+    """The A3 step 5 decision, separated from the Reconciler contract because
+    boot must *act* on it — resuming is not the same as judging settled."""
+    branch = intent.payload.get("branch")
+    if not branch:
+        return "gate"
+    if _completed_after_start(store):
+        return "settled"  # it finished; the intent merely outlived its commit
+    if not git_repo.branch_exists(str(branch)):
+        return "absent"  # the crash landed before any work existed
+    events = store.read_events()
+    if not events:
+        return "gate"
+    last = events[-1].event
+    if isinstance(last, ToolCall):
+        # A call with no recorded result: its effect is unknown and cannot be
+        # verified by inspection, so gate (A3).
+        return "gate"
+    if not isinstance(last, AssistantText | ToolResult):
+        return "gate"
+    return "resume"
+
+
+def _completed_after_start(store: StateStore) -> bool:
+    """True when the last delegation event in the log is a completion."""
+    for stored in reversed(store.read_events()):
+        if isinstance(stored.event, DelegationCompleted):
+            return True
+        if isinstance(stored.event, DelegationStarted):
+            return False
+    return False