1.2.3

Calibrates worker commute distances against real Charleston travel.

Charleston is not transit-oriented — people drive a long way to work — but depot's default distance decay exponents assume otherwise, and every worker flow into a special demand point was coming out far too tight.

The base demand already holds the evidence. Its LODES commutes are real Charleston journeys: a 13.9 km median, 34.8 km at the 90th percentile. Measured against that, the exponents are now set explicitly rather than left at the type default:

flow	exponent	median commute
School staff	2.5 → 1.2	9.5 → 13.4 km
Military personnel	1.2 → 0.8	11.9 → 14.4 km
Resort staff	2.0 → 1.2	0.3 → 24.7 km

The resort figure was the real defect. At the default exponent of 2.0 the median resort worker lived 300 metres from the resort — the barrier islands have almost no residents of their own, so a steep decay handed the entire staff to the handful who are there. Kiawah and Seabrook service staff are priced off the islands and drive in from Johns Island and West Ashley, which is what 1.2 reproduces.

Categories whose capacity is patients, shoppers or visitors rather than staff are deliberately unchanged — non-work travel genuinely is shorter than commuting, and those sites' own employees arrive through merge_within already carrying their real LODES commutes. Pupils keep their short trips because they are zoned.

Also fixes a latent ordering bug on the full-rebuild path, where the lodging clusters' airport links could bind to the wrong point silently.

Demand totals 607,276 across 2,361 points and 67,890 pops, rebuilt from seed. Map files are unchanged from 1.2.0.