fix(gateway): working exits for wedged agents + declare_coverage roll-up unblock (#341)

A live task burned 5+ hours because every exit was locked. unclaim now
works from verifying and needs_revision (service guard + lifecycle edge);
the circuit breaker and the i_am_done push-failure remediate name the
working chain ending in unclaim(); sync_branch(stash=true) clears the
DIRTY_WORKSPACE dead-end (pop-conflict preserves the stash); blocking a
task QA already owns now says to idle instead of listing states; the
orchestrator auto-block logs real errors and skips states where blocking
is meaningless instead of force-blocking them.

declare_coverage (cell/main PM) retroactively stamps parent-AC refs on a
child that implements them -- closing the roll-up deadlock where the
declaring child was cancelled and its re-delegated replacement completed
the work uncredited. Cancelling a ref-declaring child now warns and
surfaces the orphaned criteria.

Co-authored-by: Renn F <rennf93@users.noreply.github.com>

tests/unit/agent_sdk/test_verb_circuit_breaker.py

@@ -236,6 +236,7 @@ def test_check_returns_envelope_at_or_above_limit() -> None:
     assert "i_am_done" in result["message"]
     assert result["remediate"] is not None
     assert "i_am_blocked" in result["remediate"]
+    assert "unclaim" in result["remediate"]
 
 
 def test_check_returns_none_for_unlimited_retry_verbs() -> None:
@@ -511,6 +512,7 @@ def test_slow_drip_never_trips_window_but_trips_absolute_cap() -> None:
     assert result["error"] == "circuit_open"
     assert "absolute cap" in result["message"]
     assert "i_am_blocked" in result["remediate"]
+    assert "unclaim" in result["remediate"]
 
 
 def test_absolute_check_returns_none_below_cap() -> None: