Add 8-hour default window for legacy-meter deploy monitoring

Expose hours query param on /legacy-meter/summary and weekly-review;
capture_legacy_meter_evidence.py defaults to --hours 8 (--days 7 for
weekly retirement gate). Re-capture post-deploy evidence with tighter window.

tests/test_legacy_meter.py

@@ -93,6 +93,25 @@ class TestWorkplanAliasesAndLegacyMeter:
         assert item["window"]["components"] == {"old-client": 1}
         assert item["retirement_candidate"] is False
 
+    async def test_weekly_review_accepts_hours_window(self, client):
+        r = await client.post("/legacy-meter/interfaces", json={
+            "interface_key": "rest_api:GET /hour-window",
+            "interface_kind": "rest_api",
+            "replacement_ref": "/workplans/",
+            "replacement_verified": True,
+        })
+        assert r.status_code == 201, r.text
+
+        review = (await client.get("/legacy-meter/weekly-review?hours=8")).json()
+        window_seconds = (
+            datetime.fromisoformat(review["window_end"].replace("Z", "+00:00"))
+            - datetime.fromisoformat(review["window_start"].replace("Z", "+00:00"))
+        ).total_seconds()
+        assert 8 * 3600 - 5 <= window_seconds <= 8 * 3600 + 5
+
+        bad = await client.get("/legacy-meter/weekly-review?days=7&hours=8")
+        assert bad.status_code == 422
+
     async def test_weekly_review_reports_unused_verified_legacy_interface(self, client):
         r = await client.post("/legacy-meter/interfaces", json={
             "interface_key": "rest_api:GET /obsolete",