fix: stabilize test suite and repair frontend/backend wiring

- meshcore pin >=2.3.0 (EventType.STATS_CORE floor); setup.sh derives
  optional packages from requirements.txt; Python 3.10 warning
- agent-mode wifi clients proxy route + bare-array response handling
- remove dead AIS/ACARS/VDL2 SPA wiring and orphaned partials/CSS
- agent TLE download to data/tle/ (was littering repo root as gp.php)
- gate deferred background init off under pytest (mock-pollution race)
- complete Popen mocks (context manager protocol, communicate tuples)
- real pipe fds in weather-sat decoder tests (fd 10/11 collision caused
  10s SQLite stalls); satellite tests no longer rewrite data/satellites.py
- register 'live' pytest marker, excluded by default
- update stale test assertions to current APIs

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

utils/meshcore.py

@@ -35,21 +35,10 @@ def is_meshcore_available() -> bool:
     return HAS_MESHCORE
 
 
-# Try to import ContactType for repeater detection
-try:
-    from meshcore import ContactType as _ContactType
-
-    _REPEATER_TYPE = getattr(_ContactType, "REPEATER", None)
-except Exception:
-    _ContactType = None
-    _REPEATER_TYPE = None
-
-
 def _is_repeater_contact(contact_dict: dict) -> bool:
     """Return True if this contact is a repeater node."""
-    if _REPEATER_TYPE is not None:
-        return contact_dict.get("type") == _REPEATER_TYPE
-    # Fallback: meshcore repeaters have type==2 by convention
+    # meshcore exports no ContactType enum (checked through 2.3.7);
+    # repeaters have type==2 by library convention
     return contact_dict.get("type") == 2