Startup and size arithmetic

Implement static (long bytes, double startupMs) DeployCost(string model, int appBytes, double jitMs) describing deployment costs conceptually: "framework-dependent" → bytes = appBytes + 60_000_000 runtime is NOT bundled (return appBytes, jitMs + 120 for first-call JIT); "self-contained" → bytes = appBytes + 65_000_000, startupMs = jitMs + 120; "trimmed" → bytes = appBytes + 25_000_000, startupMs = jitMs + 120; "aot" → bytes = appBytes + 18_000_000, startupMs = 2.0 (no JIT). The graded point: AOT pays no JIT tax; the others all carry it.