Rebrand StreamHoard, strip Emergent.sh platform artifacts

- Remove .emergent/ state dir, tracked .gitconfig, @emergentbase/visual-edits
  dep + craco wiring, emergent.sh script/meta tags, PostHog telemetry snippet
- Rename UI/docs branding Kino -> StreamHoard (README, DEPLOY.md, Navbar,
  Login, Register, AdminShowEpisodes, FastAPI title, health check response)
- Rename docker-compose container/network names to streamhoard-*
- Default admin email domain -> admin@streamhoard.local

backend/tests/test_phase4_queue.py

@@ -17,7 +17,7 @@ import pytest
 import requests
 
 BASE_URL = os.environ["REACT_APP_BACKEND_URL"].rstrip("/")
-ADMIN_EMAIL = "admin@kino.local"
+ADMIN_EMAIL = "admin@streamhoard.local"
 ADMIN_PASSWORD = "kino-admin-2026"
 QTEST_VIDEO = "/tmp/qtest.mp4"
 
@@ -40,7 +40,7 @@ def admin_token(api):
 
 @pytest.fixture(scope="session")
 def member_token(api):
-    email = f"TEST_q_{uuid.uuid4().hex[:8]}@kino.local"
+    email = f"TEST_q_{uuid.uuid4().hex[:8]}@streamhoard.local"
     r = api.post(f"{BASE_URL}/api/auth/register",
                  json={"email": email, "password": "pass1234", "name": "QTest"},
                  headers={"Content-Type": "application/json"})