Add ground station automation with 6-phase implementation

Phase 1 - Automated observation engine:
- utils/ground_station/scheduler.py: GroundStationScheduler fires at AOS/LOS,
  claims SDR, manages IQBus lifecycle, emits SSE events
- utils/ground_station/observation_profile.py: ObservationProfile dataclass + DB CRUD
- routes/ground_station.py: REST API for profiles, scheduler, observations, recordings,
  rotator; SSE stream; /ws/satellite_waterfall WebSocket
- DB tables: observation_profiles, ground_station_observations, ground_station_events,
  sigmf_recordings (added to utils/database.py init_db)
- app.py: ground_station_queue, WebSocket init, scheduler startup in _deferred_init
- routes/__init__.py: register ground_station_bp

Phase 2 - Doppler correction:
- utils/doppler.py: generalized DopplerTracker extracted from sstv_decoder.py;
  accepts satellite name or raw TLE tuple; thread-safe; update_tle() method
- utils/sstv/sstv_decoder.py: replace inline DopplerTracker with import from utils.doppler
- Scheduler runs 5s retune loop; calls rotator.point_to() if enabled

Phase 3 - IQ recording (SigMF):
- utils/sigmf.py: SigMFWriter writes .sigmf-data + .sigmf-meta; disk-free guard (500MB)
- utils/ground_station/consumers/sigmf_writer.py: SigMFConsumer wraps SigMFWriter

Phase 4 - Multi-decoder IQ broadcast pipeline:
- utils/ground_station/iq_bus.py: IQBus single-producer fan-out; IQConsumer Protocol
- utils/ground_station/consumers/waterfall.py: CU8→FFT→binary frames
- utils/ground_station/consumers/fm_demod.py: CU8→FM demod (numpy)→decoder subprocess
- utils/ground_station/consumers/gr_satellites.py: CU8→cf32→gr_satellites (optional)

Phase 5 - Live spectrum waterfall:
- static/js/modes/ground_station_waterfall.js: /ws/satellite_waterfall canvas renderer
- Waterfall panel in satellite dashboard sidebar, auto-shown on iq_bus_started SSE event

Phase 6 - Antenna rotator control (optional):
- utils/rotator.py: RotatorController TCP client for rotctld (Hamlib line protocol)
- Rotator panel in satellite dashboard; silently disabled if rotctld unreachable

Also fixes pre-existing test_weather_sat_predict.py breakage:
- utils/weather_sat_predict.py: rewritten with self-contained skyfield implementation
  using find_discrete (matching what committed tests expected); adds _format_utc_iso
- tests/test_weather_sat_predict.py: add _MOCK_WEATHER_SATS and @patch decorators
  for tests that assumed NOAA-18 active (decommissioned Jun 2025, now active=False)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app.py

@@ -274,6 +274,9 @@ dsc_lock = threading.Lock()
 tscm_queue = queue.Queue(maxsize=QUEUE_MAX_SIZE)
 tscm_lock = threading.Lock()
 
+# Ground Station automation
+ground_station_queue = queue.Queue(maxsize=QUEUE_MAX_SIZE)
+
 # SubGHz Transceiver (HackRF)
 subghz_queue = queue.Queue(maxsize=QUEUE_MAX_SIZE)
 subghz_lock = threading.Lock()
@@ -1149,6 +1152,13 @@ def _init_app() -> None:
     except ImportError:
         pass
 
+    # Initialize WebSocket for ground station live waterfall
+    try:
+        from routes.ground_station import init_ground_station_websocket
+        init_ground_station_websocket(app)
+    except ImportError:
+        pass
+
     # Defer heavy/network operations so the worker can serve requests immediately
     import threading
 
@@ -1196,6 +1206,22 @@ def _init_app() -> None:
         except Exception as e:
             logger.warning(f"SatNOGS prefetch failed: {e}")
 
+        # Wire ground station scheduler event → SSE queue
+        try:
+            import app as _self
+            from utils.ground_station.scheduler import get_ground_station_scheduler
+            gs_scheduler = get_ground_station_scheduler()
+
+            def _gs_event_to_sse(event: dict) -> None:
+                try:
+                    _self.ground_station_queue.put_nowait(event)
+                except Exception:
+                    pass
+
+            gs_scheduler.set_event_callback(_gs_event_to_sse)
+        except Exception as e:
+            logger.warning(f"Ground station scheduler init failed: {e}")
+
     threading.Thread(target=_deferred_init, daemon=True).start()