Add Kaintuck, an original two-phase frontier game

#28 in Riparion/riparion-retro — merged 2026-06-11

A new mobile-first WASM Dioxus game at games/kaintuck/ — an original design that fuses two engines already in the collection:

• Phase 1 — The River (Pittsburgh → Natchez): taipan-style cargo trading. Build a boat (Skiff/Flatboat/Broadhorn) and hire crew on boatyard credit, load 7 goods, ride a downstream Voyage hazard chain (sandbars, snags, river pirates, spoilage, desertion, floods), the Falls of the Ohio set-piece, then sell everything + the boat for lumber at Natchez Under-the-Hill.
• Phase 2 — The Trace (Natchez → Nashville): oregon-trail-style distance walk. Pace/company choices, the stands, Sam Mason & the Harpe brothers, swamp fever, getting lost, and the Duck River ford — scored on cash, surviving crew, reputation, and whether you were robbed.

One serializable Game with a phase field gates which half is live; the Mode enum spans both. All six hazards wire into minigames-kit (steady_hands, quickdraw, crowd_threading, timing_bar, sequence, bucket_brigade).

Verification

• 17 host engine tests pass, including a 7-seed scripted full playthrough (River → Natchez → Trace → ending) asserting invariants.
• cargo clippy --workspace --all-targets — zero warnings.
• Driven in a real browser at 390×844 across both phases (build, credit-funded trade, town market, save/resume, QuickDraw, Natchez, victory reckoning) — zero console errors.
• Release build succeeds with --debug-symbols false; the in-game screenshot.png was captured from it.
• Flatboat icon glyph added to gen-icons.mjs (full icon set generated); game README + root README row added.

🤖 Generated with Claude Code