Implement REIN-A-0002 ops_run claim loop and approach registry.

Add activity-core ops_run client, approach selection (FI/Binky/mail/agent),
claim-loop worker with lease heartbeat, CLI run --from-ops-run and claim-loop,
install units, and docs demoting issue-core to legacy external tickets.
T05 timer cutover remains operator after five clean cycles.

tests/test_approaches.py

@@ -0,0 +1,92 @@
+"""Pure approach selection tests (REIN-A-0002-T02)."""
+
+from __future__ import annotations
+
+from rein_aharness.approaches import (
+    APPROACH_AGENT_SESSION,
+    APPROACH_BRIEF_DAILY,
+    APPROACH_FI_RESEARCH_BRIEF,
+    APPROACH_MAIL_PIPELINE,
+    APPROACH_UNMATCHED,
+    select_approach,
+)
+from rein_aharness.ops_run_client import OpsRun
+
+
+def _run(**kwargs) -> OpsRun:
+    base = dict(
+        id="r",
+        activity_definition_id="",
+        idempotency_key="k",
+        target_repo="x",
+        title="",
+        description="",
+        labels=[],
+    )
+    base.update(kwargs)
+    return OpsRun(**base)
+
+
+def test_select_fi_by_label() -> None:
+    assert (
+        select_approach(
+            _run(labels=["automated", "research-brief", "freedom-intelligence"])
+        )
+        == APPROACH_FI_RESEARCH_BRIEF
+    )
+
+
+def test_select_fi_by_blob() -> None:
+    assert (
+        select_approach(
+            _run(
+                labels=["automated"],
+                activity_definition_id="fi-daily-research-brief",
+                title="FI daily research brief",
+            )
+        )
+        == APPROACH_FI_RESEARCH_BRIEF
+    )
+
+
+def test_select_binky_rhythm() -> None:
+    assert (
+        select_approach(_run(labels=["binky", "rhythm", "automated"]))
+        == APPROACH_BRIEF_DAILY
+    )
+
+
+def test_select_mail_intake() -> None:
+    assert (
+        select_approach(_run(labels=["mail-intake", "automated"]))
+        == APPROACH_MAIL_PIPELINE
+    )
+
+
+def test_select_agent_session() -> None:
+    assert (
+        select_approach(_run(labels=["agent-session", "automated"]))
+        == APPROACH_AGENT_SESSION
+    )
+
+
+def test_select_hint_overrides() -> None:
+    assert (
+        select_approach(
+            _run(labels=["automated"], approach_hint="fi-research-brief")
+        )
+        == APPROACH_FI_RESEARCH_BRIEF
+    )
+
+
+def test_unmatched() -> None:
+    assert select_approach(_run(labels=["automated"], title="misc hygiene")) == (
+        APPROACH_UNMATCHED
+    )
+
+
+def test_fi_before_generic_automated() -> None:
+    """research-brief must not fall through to unmatched when only automated."""
+    assert (
+        select_approach(_run(labels=["research-brief"])) == APPROACH_FI_RESEARCH_BRIEF
+    )