S3 review: overview pool-cap check, membership re-read on pool_full (server-26#225)

- guild_overview offered an invite link to a full pool bot whenever it was
  in ANY server (`if member` tested the non-empty guild_ids list, not
  membership of this guild). Now: in this guild, or invitable.
- start_stream re-reads membership once on pool_full as it already does on
  no_bot_in_guild, so a full pool bot an admin just invited by hand is found.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

drb-c2-core/tests/test_discord_perm_check.py

@@ -446,6 +446,32 @@ def test_voice_check_lists_invites_within_the_pool_cap(fs, monkeypatch):
     assert [i["name"] for i in out["invite"]] == ["DRB Radio room"]
 
 
+def test_pool_full_rereads_membership_once(fs, monkeypatch):
+    # A full pool bot an admin just invited by hand: guild_ids is stale, so
+    # the first pick says pool_full; one membership re-read must still find it.
+    monkeypatch.setattr(settings, "discord_pool_bot_guild_cap", 2)
+    _token(fs, "full", guilds=("1", "2"))
+
+    async def _refresh(token_ids):
+        assert token_ids == ["full"]
+        fs.put("bot_tokens", "full", {**fs.get("bot_tokens", "full"), "guild_ids": ["1", "2", GUILD]})
+        return 1
+    monkeypatch.setattr(discord_rest, "refresh_membership", _refresh)
+    assert run(_start())["token_id"] == "full"
+
+
+def test_bot_overview_never_offers_a_full_pool_bot(fs, monkeypatch):
+    # A pool bot in other servers (non-empty guild_ids) at the cap must not get
+    # an invite link; one already in this server keeps its link.
+    monkeypatch.setattr(settings, "discord_pool_bot_guild_cap", 2)
+    _token(fs, "full", guilds=("1", "2"))
+    _token(fs, "room", guilds=("1",))
+    _token(fs, "here", guilds=("1", GUILD))
+    out = run(discord_router.guild_overview(GUILD, {"service": True}))
+    links = {b["token_id"]: b["invite_url"] for b in out["bots"]}
+    assert links["full"] is None and links["room"] and links["here"]
+
+
 def test_voice_check_busy_and_other_node(fs):
     _token(fs, "t1", lease={"node_id": "n2", "streams": [], "lease_id": "L"})
     out = run(checks.node_voice_check("n1", GUILD, refresh=0, channel_id="1001", decoded=OWNER))