Help me plan my long‑haul journey from [home‑country] to [host‑country] with connecting flights through [connecting-countries]. Show me how to verify whether my checked baggage will be automatically transferred at each layover – covering the same‑ticket vs. separate‑ticket rules, interline agreements and what to ask at check‑in. Include how to use airline apps or tracker tools to confirm in‑flight, plus steps to take if baggage isn’t checked through.