feat(ui): Phase 30 ship-class calculator with goal-seek and reach circles

Fuse the standalone ship-class designer (Phases 17/18) into a sidebar calculator: live mass/speed/attack/defence/bombing results, a planet build-rate readout, single-target goal-seek, a modernization-cost mode, and auto reach circles on the map for the selected planet.

pkg/calc becomes the single source for the new math (no mirroring): extract BombingPower from the engine model and the per-turn ship-production loop from controller.ProduceShip into pkg/calc (engine now delegates), and add inverse goal-seek solvers in pkg/calc/solve.go. Thin-bridge the combat, planet-build, and solver functions through ui/core/calc + ui/wasm and rebuild core.wasm.

Remove the standalone designer view/route; the ship-classes table and the view/bottom menus open the calculator via a shared request store.

Docs: rewrite ui/PLAN.md Phase 30, adjust Phase 34 (realistic forecast + CAP/COL ownership), add ui/docs/calculator-ux.md, extend calc-bridge.md, fix navigation.md; remove ui/CALCULATOR.md.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

pkg/calc/ship.go

@@ -94,3 +94,14 @@ func EffectiveDefence(
 	}
 	return defendingShields * defendingShiledsTech / math.Pow(defendingFullMass, 1./3.) * math.Pow(30., 1./3.)
 }
+
+// BombingPower returns the bombing power of number ships whose weapons
+// block is weapons, built at weapons tech level weaponsTech and carrying
+// armament weapon mounts. The leading factor sqrt(weapons*weaponsTech)/10
+// + 1 makes the power grow super-linearly with effective weapon strength,
+// which then scales linearly with weapons, weaponsTech, armament, and
+// number. With zero armament or zero weapons the power is zero.
+func BombingPower(weapons, weaponsTech, armament, number float64) float64 {
+	return (math.Sqrt(weapons*weaponsTech)/10. + 1.) *
+		weapons * weaponsTech * armament * number
+}