ui/phase-20: ship-group inspector actions

Eight ship-group operations land on the inspector behind a single
inline-form panel: split, send, load, unload, modernize, dismantle,
transfer, join fleet. Each action either appends a typed command to
the local order draft or surfaces a tooltip explaining the
disabled state. Partial-ship operations emit an implicit
breakShipGroup command before the targeted action so the engine
sees a clean (Break, Action) pair on the wire.

`pkg/calc.BlockUpgradeCost` migrates from
`game/internal/controller/ship_group_upgrade.go` so the calc
bridge can wrap a pure pkg/calc formula; the controller now
imports it. The bridge surfaces the function as
`core.blockUpgradeCost`, which the inspector calls once per ship
block to render the modernize cost preview.

`GameReport.otherRaces` is decoded from the report's player block
(non-extinct, ≠ self) and feeds the transfer-to-race picker. The
planet inspector's stationed-ship rows become clickable for own
groups so the actions panel is reachable from the standard click
flow (the renderer continues to hide on-planet groups).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

ui/wasm/main.go

@@ -25,6 +25,7 @@
 //   - speed(fields)             -> number
 //   - cargoCapacity(fields)     -> number
 //   - carryingMass(fields)      -> number
+//   - blockUpgradeCost(fields)  -> number          (Phase 20: modernize cost preview)
 //
 // Field objects are plain JS objects with camelCase keys matching the
 // TypeScript `Core` interface, and bytes fields are Uint8Array.
@@ -59,6 +60,7 @@ func main() {
 		"speed":             js.FuncOf(speed),
 		"cargoCapacity":     js.FuncOf(cargoCapacity),
 		"carryingMass":      js.FuncOf(carryingMass),
+		"blockUpgradeCost":  js.FuncOf(blockUpgradeCost),
 	}))
 
 	// Block forever so the Go runtime stays alive while JS keeps calling
@@ -224,6 +226,21 @@ func carryingMass(_ js.Value, args []js.Value) any {
 	return js.ValueOf(calc.CarryingMass(load, cargoTech))
 }
 
+// blockUpgradeCost bridges `calc.BlockUpgradeCost`. Input
+// `{ blockMass, currentTech, targetTech }`, output a JS number
+// (production cost of moving one block from currentTech to
+// targetTech; zero when blockMass is zero or targetTech is not
+// above currentTech).
+func blockUpgradeCost(_ js.Value, args []js.Value) any {
+	if len(args) != 1 {
+		return js.Null()
+	}
+	blockMass := args[0].Get("blockMass").Float()
+	currentTech := args[0].Get("currentTech").Float()
+	targetTech := args[0].Get("targetTech").Float()
+	return js.ValueOf(calc.BlockUpgradeCost(blockMass, currentTech, targetTech))
+}
+
 // copyBytesFromJS materialises a JS Uint8Array (or any indexable
 // byte-shaped value) into a Go byte slice. We avoid `js.CopyBytesToGo`
 // because TinyGo's implementation panics on values it does not