Stop rebase reminders for empty historical branches

src/agent_comms/standing_rules.py

@@ -593,8 +593,8 @@ def derive(cls, branches: tuple[HeldBranch, ...]) -> tuple[Self, ...]: ...
 
 @dataclass(frozen=True)
 class BranchBehindMain(CoreActsStandingRule, HeldBranchRule):
-    """A held branch needs a new base the moment main passes it. Syncing is the holder's
-    reflex, so Core tells the holder itself instead of waiting on a teammate relay."""
+    """Outstanding branch changes need a new base when main passes them. Core tells
+    the holder directly; an empty historical checkout owes no new publication."""
 
     problem: str
     holder: ThreadIncarnation
@@ -620,7 +620,7 @@ def derive(cls, branches: tuple[HeldBranch, ...]) -> tuple[Self, ...]:
         return tuple(cls(problem=held.problem, holder=held.holder,
                          repository=held.difference.repository,
                          branch=held.difference.branch, behind=held.difference.behind)
-                     for held in branches if held.difference.behind and not held.queued)
+                     for held in branches if held.difference.needs_rebase and not held.queued)
 
     def line(self) -> str:
         return (f"REBASE {self.repository.to_wire()}:{self.branch} ({self.holder.name} {self.problem}) is"

src/agent_comms/work_branches.py

@@ -220,6 +220,16 @@ class BranchDifference:
     growth: SourceGrowth
     unpublished: tuple[UnpushedHead, ...]
 
+    @property
+    def needs_rebase(self) -> bool:
+        """Only outstanding committed changes need a newer base before publication.
+
+        An ancestor of main has no outgoing delta; retaining its checkout as evidence
+        does not create work whenever main advances. Uncommitted edits remain owned
+        by the checkout and the holder's before-commit synchronization.
+        """
+        return bool(self.behind and self.files)
+
     @property
     def changes_source(self) -> bool:
         """Any file under the source tree, not only the Python modules growth counts."""

tests/test_team_replay.py

@@ -154,7 +154,6 @@ def order(self, name: str, worktree: Path, *, at: float) -> Todo:
             name,
             CreateProblemGoalAction(
                 problem=problem,
-                commander=self.commander,
                 request=self.request,
                 assigner=self.thread(self.commander).incarnation,
                 repo=self.repository,
@@ -472,6 +471,27 @@ def behind(name, number, queued):
     assert queued.id not in told
 
 
+@pytest.mark.parametrize("outstanding", (False, True))
+def test_rebase_notice_requires_outstanding_branch_changes(fleet, outstanding):
+    built, _ = fleet
+    home = built.worktree("retained-history", base=built.old_main)
+    if outstanding:
+        built.commit(home, "repair.py", "repair = 1\n")
+    built.push(home)
+    todo = built.unit("history-worker", home)
+    storage = built.comms.registry.storage_rule
+    checkout = storage.order_checkout(storage.initial_roots("history-worker"), todo.id)
+    original = built.git(checkout, "rev-parse", "HEAD")
+
+    for index in range(2):
+        built.commit(built.source.checkout, "main.py", f"count = {index + 1}\n")
+        built.git(built.source.checkout, "push", "-q", "origin", "main")
+        told = {rule.problem for rule in built.observe().rules
+                if isinstance(rule, BranchBehindMain)}
+        assert (todo.id in told) is outstanding
+        assert built.git(checkout, "rev-parse", "HEAD") == original
+
+
 def test_branch_rules_read_the_order_checkout_instead_of_the_behind_home(fleet):
     built, _ = fleet
     home = built.worktree('old-home', base=built.old_main)