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/planet_test.go

@@ -61,3 +61,52 @@ func TestShipBuildCost(t *testing.T) {
 		})
 	}
 }
+
+func TestProduceShipsInTurn(t *testing.T) {
+	cases := []struct {
+		name                                               string
+		productionAvailable, material, resources, shipMass float64
+		wantShips                                          uint
+		wantMaterialLeft, wantProductionUsed, wantProgress float64
+	}{
+		{
+			name:                "ample material: ten ships, no farming",
+			productionAvailable: 100, material: 100, resources: 10, shipMass: 1,
+			wantShips: 10, wantMaterialLeft: 90, wantProductionUsed: 0, wantProgress: 0,
+		},
+		{
+			name:                "no material: partial progress on a farmed ship",
+			productionAvailable: 114, material: 0, resources: 0.5, shipMass: 10,
+			// ShipBuildCost(10,0,0.5) = 100 + 10/0.5 = 120; 114/120 = 0.95.
+			wantShips: 0, wantMaterialLeft: 0, wantProductionUsed: 114, wantProgress: 0.95,
+		},
+		{
+			name:                "no production available leaves the stockpile",
+			productionAvailable: 0, material: 50, resources: 10, shipMass: 5,
+			wantShips: 0, wantMaterialLeft: 50, wantProductionUsed: 0, wantProgress: 0,
+		},
+		{
+			name:                "zero ship mass is guarded against an endless loop",
+			productionAvailable: 100, material: 50, resources: 10, shipMass: 0,
+			wantShips: 0, wantMaterialLeft: 50, wantProductionUsed: 0, wantProgress: 0,
+		},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			ships, materialLeft, productionUsed, progress := calc.ProduceShipsInTurn(
+				tc.productionAvailable, tc.material, tc.resources, tc.shipMass)
+			if ships != tc.wantShips {
+				t.Errorf("ships = %d, want %d", ships, tc.wantShips)
+			}
+			if math.Abs(materialLeft-tc.wantMaterialLeft) > 1e-9 {
+				t.Errorf("materialLeft = %v, want %v", materialLeft, tc.wantMaterialLeft)
+			}
+			if math.Abs(productionUsed-tc.wantProductionUsed) > 1e-9 {
+				t.Errorf("productionUsed = %v, want %v", productionUsed, tc.wantProductionUsed)
+			}
+			if math.Abs(progress-tc.wantProgress) > 1e-9 {
+				t.Errorf("progress = %v, want %v", progress, tc.wantProgress)
+			}
+		})
+	}
+}