Integrate OpenFlights API for free, no-auth flight data generation

- Added openFlightsService.js to fetch and cache OpenFlights airport/airline/routes data
- Validates airport codes exist in OpenFlights database (6072+ airports)
- Generates realistic flights using major international airlines
- Creates varied routing options: direct, 1-stop, 2-stop flights
- Updated flightService.js to use OpenFlights as primary source before Amadeus
- OpenFlights as fallback if Amadeus unavailable or returns no results
- No API keys or authentication required
- Cached locally to avoid repeated network requests
- Realistic pricing, times, and stop locations

Docker container rebuilt with OpenFlights integration.

scripts/debug_canberra.py

@@ -0,0 +1,16 @@
+import sqlite3
+
+conn = sqlite3.connect('data/travel_rates_scraped.sqlite3')
+cursor = conn.cursor()
+
+cursor.execute("""
+    SELECT city, currency, rate_type, rate_amount 
+    FROM rate_entries 
+    WHERE country = 'Australia' AND city LIKE '%Canberra%' 
+    ORDER BY city, rate_type
+""")
+
+for row in cursor.fetchall():
+    print(row)
+
+conn.close()