Add Listening Post, improve setup and documentation

- Add Listening Post mode with frequency scanner and audio monitoring
- Add dependency warning for aircraft dashboard listen feature
- Auto-restart audio when switching frequencies
- Fix toolbar overflow on aircraft dashboard custom frequency
- Update setup script with full macOS/Debian support
- Clean up README and documentation for clarity
- Add sox and dump1090 to Dockerfile
- Add comprehensive tool reference to HARDWARE.md
- Add correlation, settings, and database utilities
- Add new test files for routes, validation, correlation, database

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

utils/constants.py

@@ -0,0 +1,213 @@
+"""
+INTERCEPT - Constants and Magic Numbers
+
+Centralized location for all hardcoded values used throughout the application.
+This improves maintainability and makes the codebase self-documenting.
+"""
+
+from __future__ import annotations
+
+# =============================================================================
+# NETWORK PORTS
+# =============================================================================
+
+# ADS-B SBS data output port (dump1090 default)
+ADSB_SBS_PORT = 30003
+
+# GPS daemon port (gpsd default)
+GPSD_PORT = 2947
+
+# RTL-TCP server port (rtl_tcp default)
+RTL_TCP_PORT = 1234
+
+
+# =============================================================================
+# PROCESS TIMEOUTS (seconds)
+# =============================================================================
+
+# General process termination timeout
+PROCESS_TERMINATE_TIMEOUT = 2
+
+# ADS-B process termination (dump1090 needs longer)
+ADSB_TERMINATE_TIMEOUT = 5
+
+# WiFi process termination (airodump-ng)
+WIFI_TERMINATE_TIMEOUT = 3
+
+# Bluetooth process termination
+BT_TERMINATE_TIMEOUT = 3
+
+# PMKID process termination
+PMKID_TERMINATE_TIMEOUT = 5
+
+# Socket connection timeout
+SOCKET_CONNECT_TIMEOUT = 2
+
+# SBS stream socket timeout
+SBS_SOCKET_TIMEOUT = 5
+
+# Subprocess command timeout (short operations)
+SUBPROCESS_TIMEOUT_SHORT = 5
+
+# Subprocess command timeout (medium operations)
+SUBPROCESS_TIMEOUT_MEDIUM = 10
+
+# Subprocess command timeout (long operations like airmon-ng)
+SUBPROCESS_TIMEOUT_LONG = 15
+
+# External HTTP request timeout (TLE fetching, etc.)
+HTTP_REQUEST_TIMEOUT = 10
+
+# Deauth command timeout
+DEAUTH_TIMEOUT = 30
+
+# Service enumeration timeout (sdptool browse)
+SERVICE_ENUM_TIMEOUT = 30
+
+
+# =============================================================================
+# SSE (Server-Sent Events) SETTINGS
+# =============================================================================
+
+# Keepalive interval for SSE streams (seconds)
+SSE_KEEPALIVE_INTERVAL = 30.0
+
+# Queue get timeout for SSE generators (seconds)
+SSE_QUEUE_TIMEOUT = 1.0
+
+
+# =============================================================================
+# DATA RETENTION / CLEANUP (seconds)
+# =============================================================================
+
+# Maximum age for aircraft data before cleanup
+MAX_AIRCRAFT_AGE_SECONDS = 300  # 5 minutes
+
+# Maximum age for WiFi network data before cleanup
+MAX_WIFI_NETWORK_AGE_SECONDS = 600  # 10 minutes
+
+# Maximum age for Bluetooth device data before cleanup
+MAX_BT_DEVICE_AGE_SECONDS = 300  # 5 minutes
+
+# ADS-B queue batch update interval
+ADSB_UPDATE_INTERVAL = 1.0  # seconds
+
+
+# =============================================================================
+# QUEUE LIMITS
+# =============================================================================
+
+# Maximum queue size for all data queues
+QUEUE_MAX_SIZE = 1000
+
+# GPS queue size (smaller, more frequent updates)
+GPS_QUEUE_MAX_SIZE = 100
+
+
+# =============================================================================
+# DATA PARSING
+# =============================================================================
+
+# WiFi CSV parse interval (seconds)
+WIFI_CSV_PARSE_INTERVAL = 2.0
+
+# Minimum time before warning about no CSV data
+WIFI_CSV_TIMEOUT_WARNING = 5.0
+
+# Socket receive buffer size
+SOCKET_BUFFER_SIZE = 4096
+
+# PTY read buffer size
+PTY_BUFFER_SIZE = 1024
+
+
+# =============================================================================
+# EXTERNAL SERVICE LIMITS
+# =============================================================================
+
+# Maximum response size for external HTTP requests (bytes)
+MAX_HTTP_RESPONSE_SIZE = 1024 * 1024  # 1 MB
+
+# Deauth packet count limits
+MIN_DEAUTH_COUNT = 1
+MAX_DEAUTH_COUNT = 100
+DEFAULT_DEAUTH_COUNT = 5
+
+
+# =============================================================================
+# VALIDATION LIMITS
+# =============================================================================
+
+# Squelch range
+MIN_SQUELCH = 0
+MAX_SQUELCH = 1000
+
+# Valid GPS baudrates
+VALID_GPS_BAUDRATES = [4800, 9600, 19200, 38400, 57600, 115200]
+
+# Port range
+MIN_PORT = 1
+MAX_PORT = 65535
+
+
+# =============================================================================
+# SATELLITE TRACKING
+# =============================================================================
+
+# Default observer location (London)
+DEFAULT_LATITUDE = 51.5074
+DEFAULT_LONGITUDE = -0.1278
+
+# Allowed TLE hosts for security
+ALLOWED_TLE_HOSTS = [
+    'celestrak.org',
+    'celestrak.com',
+    'www.celestrak.org',
+    'www.celestrak.com'
+]
+
+# Earth radius (km) - WGS84 mean
+EARTH_RADIUS_KM = 6371
+
+# Trajectory calculation points
+TRAJECTORY_POINTS = 30
+GROUND_TRACK_POINTS = 60
+ORBIT_TRACK_RANGE_MINUTES = 45
+
+
+# =============================================================================
+# SLEEP/DELAY TIMES (seconds)
+# =============================================================================
+
+# Wait after starting process before checking status
+PROCESS_START_WAIT = 0.5
+
+# Wait after dump1090 start before connecting
+DUMP1090_START_WAIT = 3.0
+
+# Delay between monitor mode operations
+MONITOR_MODE_DELAY = 1.0
+
+# Bluetooth adapter reset delays
+BT_RESET_DELAY = 0.5
+BT_ADAPTER_DOWN_WAIT = 1.0
+
+# SBS reconnection delay on error
+SBS_RECONNECT_DELAY = 2.0
+
+
+# =============================================================================
+# FILE PATHS
+# =============================================================================
+
+# Default pager log file
+DEFAULT_PAGER_LOG_FILE = 'pager_messages.log'
+
+# WiFi capture temp path prefix
+WIFI_CAPTURE_PATH_PREFIX = '/tmp/intercept_wifi'
+
+# Handshake capture path prefix
+HANDSHAKE_CAPTURE_PATH_PREFIX = '/tmp/intercept_handshake_'
+
+# PMKID capture path prefix
+PMKID_CAPTURE_PATH_PREFIX = '/tmp/intercept_pmkid_'