Closer to Home: gate "Near you" on high/medium confidence (both modes)

Codex polish before deploy: anything elevated as Near you / Close to home must have
geo_confidence in (high, medium) — the feature's promise is relevance. Country-only
mode now gates "near" too; since it has no "country" tier, the "world" scope is
widened to absorb low-confidence home-country stories so they surface there instead
of vanishing between tiers (the same edge-case class, fixed). State mode unchanged.

364 tests green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

tests/test_geo_feed.py

@@ -67,13 +67,18 @@ def test_sparse_near_folds_into_country(app_db):
     assert "country" in _sections(r["items"])           # US stories still surface as your country
 
 
-def test_country_only_home_has_no_country_tier(app_db):
+def test_country_only_home_gates_near_on_confidence(app_db):
     r = TestClient(app_db).get("/api/feed?home=US&limit=50").json()
-    secs = set(_sections(r["items"]))
+    items = r["items"]
+    secs = set(_sections(items))
     assert "country" not in secs                        # no state -> near IS the whole country
     assert secs <= {"near", "world"}
-    near_ids = {it["id"] for it in r["items"] if it["section"] == "near"}
-    assert near_ids == {1, 2, 3, 4, 5, 6, 7, 8}         # all US (incl. the low-conf one, country match)
+    near_ids = {it["id"] for it in items if it["section"] == "near"}
+    # "Near you" requires high/medium confidence: high-conf US stories only, NOT the
+    # low-confidence US story (#5), which must still appear, in "world".
+    assert near_ids == {1, 2, 3, 4, 6, 7, 8}
+    a5 = next(it for it in items if it["id"] == 5)
+    assert a5["section"] == "world"                      # low-conf home-country -> world, not vanished
 
 
 def test_no_home_is_unchanged_and_unsectioned(app_db):