Layover & Long Transit Optimizer

You are an experienced frequent flyer. Help me plan a layover optimally.

=== INPUTS ===
Layover City: {{CITY}}
Layover Length: {{HOURS}} (e.g., 7 hours, 12 hours, overnight)
Arrival Time at Airport: {{ARRIVAL_TIME}}
Departure Time: {{DEPARTURE_TIME}}
Visa Situation: {{VISA}} (do I need a transit visa for this country?)
Bags: {{BAGS}} (carry-on only / checked bags need recheck)
Physical Energy Level: {{ENERGY}} (exhausted from long flight / fine)
Priority: {{PRIORITY}} (sleep / eat well / see the city / airport lounge)

=== STEP 1: FEASIBILITY CHECK ===

Is it worth leaving the airport? Calculate:
- Minimum time to clear immigration inbound
- Transit time airport → city center
- Time in the city
- Transit back + buffer
- Minimum time to clear check-in, security, and gate on the way out
- **Total usable city time**: [X hours]

Rule of thumb:
- Under 3 hours usable: stay at airport
- 3-5 hours: quick city dash IF airport is <30 min away
- 5-8 hours: realistic half-day trip
- 8+ hours: near full-day mini trip
- Overnight: hotel + city time

=== STEP 2: VISA AND DOCUMENTS CHECK ===
Based on the destination, tell me:
- Is a transit visa required for my passport?
- Are there visa-free transit zones or TWOV programs?
- If yes to visa, can I get one on arrival?
- Document prep needed

=== STEP 3: IF STAYING AT AIRPORT ===
Best option for the priority:
- **Sleep**: Lounges with sleep pods, Minute Suites, capsule hotels in the terminal
- **Eat well**: Best terminal restaurants (beyond fast food)
- **Work**: Quiet lounges with power and Wi-Fi
- **Shower**: Lounge access with shower facilities
- **Pay per use vs. lounge pass math**: what's cheapest for my needs

=== STEP 4: IF LEAVING AIRPORT ===

**Transit plan**
- Fastest airport → city route (train, express bus, taxi, subway)
- Cost + time
- Luggage storage at airport if bags can't come
- SIM / eSIM for the day

**Mini-itinerary (realistic for X hours in city)**
- 1-2 anchor activities max
- One meal
- A place to sit/relax
- Safety buffer back to airport

**Time budget**
| Activity | Start | End | Notes |

=== OUTPUT ===
Feasibility verdict + visa check + (airport plan OR city mini-itinerary) + transit logistics + safety buffer + emergency return plan.