Act immediately on flagged signups Mastodon already auto-approved

account.approved never fires for a signup that went through open
registration without ever being queued (no prior block on that
address). process_signup was waiting on that event forever, so the
first flagged signup on any new bad IP/email domain never got welcomed
or watched by the suspicious-sweep. Now checks Admin::Account.approved
from the account.created payload and acts immediately if it's already
true.

test_local.py

@@ -263,6 +263,17 @@ def ip_scrutiny_tests():
     main.send_welcome("102", "dc1")  # simulate account.approved's unconditional welcome
     assert ("102", "dc1") in sent, sent
 
+    # B2. datacenter IP, held, but Mastodon already auto-approved the signup
+    #     (open registration, never queued) -> account.approved will never
+    #     fire, so process_signup must welcome + start the watch immediately
+    #     instead of waiting for an event that isn't coming.
+    sent.clear(); dms.clear(); ipblocks.clear()
+    classifications["198.51.100.22"] = ("datacenter", "Example Cloud Hosting Inc", True)
+    main.process_signup("104", "dc3", "198.51.100.22", "", True)
+    assert ("104", "dc3") in sent, "already-approved flagged signup must be welcomed immediately"
+    assert main.get_signup_flag("104") is True
+    assert main.already_watched_suspicious("104"), "already-approved flagged signup must start its watch immediately"
+
     # C. same datacenter IP, but IP_SCRUTINY_DRY_RUN -> welcomed immediately
     #    (no hold), no ip-block write, DM carries the dry-run prefix.
     sent.clear(); dms.clear(); ipblocks.clear()