Add weather satellite decoder for NOAA APT and Meteor LRPT

New module for receiving and decoding weather satellite images using
SatDump CLI. Supports NOAA-15/18/19 (APT) and Meteor-M2-3 (LRPT)
with live SDR capture, pass prediction, and image gallery.

Backend:
- utils/weather_sat.py: SatDump process manager with image watcher
- routes/weather_sat.py: API endpoints (start/stop/images/passes/stream)
- SSE streaming for real-time capture progress
- Pass prediction using existing skyfield + TLE data
- SDR device registry integration (prevents conflicts)

Frontend:
- Sidebar panel with satellite selector and antenna build guide
  (V-dipole and QFH instructions for 137 MHz reception)
- Stats strip with status, frequency, mode, location inputs
- Split-panel layout: upcoming passes list + decoded image gallery
- Full-size image modal viewer
- SSE-driven progress updates during capture

Infrastructure:
- Dockerfile: Add SatDump build from source (headless CLI mode)
  with runtime deps (libpng, libtiff, libjemalloc, libvolk2, libnng)
- Config: WEATHER_SAT_GAIN, SAMPLE_RATE, MIN_ELEVATION, PREDICTION_HOURS
- Nav: Weather Sat entry in Space group (desktop + mobile)

https://claude.ai/code/session_01FjLTkyELaqh27U1wEXngFQ

routes/__init__.py

@@ -26,6 +26,7 @@ def register_blueprints(app):
     from .offline import offline_bp
     from .updater import updater_bp
     from .sstv import sstv_bp
+    from .weather_sat import weather_sat_bp
 
     app.register_blueprint(pager_bp)
     app.register_blueprint(sensor_bp)
@@ -51,6 +52,7 @@ def register_blueprints(app):
     app.register_blueprint(offline_bp)  # Offline mode settings
     app.register_blueprint(updater_bp)  # GitHub update checking
     app.register_blueprint(sstv_bp)  # ISS SSTV decoder
+    app.register_blueprint(weather_sat_bp)  # NOAA/Meteor weather satellite decoder
 
     # Initialize TSCM state with queue and lock from app
     import app as app_module