Refactor into modular structure with improvements

- Split monolithic intercept.py (15k lines) into modular structure:
  - routes/ - Flask blueprints for each feature
  - templates/ - Jinja2 HTML templates
  - data/ - OUI database, satellite TLEs, detection patterns
  - utils/ - dependencies, process management, logging
  - config.py - centralized configuration with env var support

- Add type hints to function signatures
- Replace bare except clauses with specific exceptions
- Add proper logging module (replaces print statements)
- Add environment variable support (INTERCEPT_* prefix)
- Add test suite with pytest
- Add Dockerfile for containerized deployment
- Add pyproject.toml with ruff/black/mypy config
- Add requirements-dev.txt for development dependencies

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

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

tests/test_app.py

@@ -0,0 +1,39 @@
+"""Tests for main application routes."""
+
+import pytest
+
+
+def test_index_page(client):
+    """Test that index page loads."""
+    response = client.get('/')
+    assert response.status_code == 200
+    assert b'INTERCEPT' in response.data
+
+
+def test_dependencies_endpoint(client):
+    """Test dependencies endpoint returns valid JSON."""
+    response = client.get('/dependencies')
+    assert response.status_code == 200
+    data = response.get_json()
+    assert 'modes' in data
+    assert 'os' in data
+
+
+def test_devices_endpoint(client):
+    """Test devices endpoint returns list."""
+    response = client.get('/devices')
+    assert response.status_code == 200
+    data = response.get_json()
+    assert isinstance(data, list)
+
+
+def test_satellite_dashboard(client):
+    """Test satellite dashboard loads."""
+    response = client.get('/satellite/dashboard')
+    assert response.status_code == 200
+
+
+def test_adsb_dashboard(client):
+    """Test ADS-B dashboard loads."""
+    response = client.get('/adsb/dashboard')
+    assert response.status_code == 200