ui/phase-9: PixiJS map renderer with torus and no-wrap modes

Stand up the vector map renderer in ui/frontend/src/map/ on top of
PixiJS v8 + pixi-viewport@^6. Torus mode renders nine container
copies for seamless wrap; no-wrap mode pins the camera at world
bounds and centres on an axis when the viewport exceeds the world
along that axis. Hit-test is a brute-force pass with deterministic
[-priority, distSq, kindOrder, id] ordering and torus-shortest
distance, validated by hand-built unit cases.

The development playground at /__debug/map exposes a window
debug surface for the Playwright spec, which forces WebGPU on
chromium-desktop, WebGL on webkit-desktop, and accepts the
auto-picked backend on mobile projects.

Algorithm spec lives in ui/docs/renderer.md, which also pins the
new deprecation status of galaxy/client (the entire Fyne client
module, including client/world). client/world/README.md and the
Phase 9 stub in ui/PLAN.md gain matching deprecation banners.

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

ui/frontend/src/map/index.ts

@@ -0,0 +1,45 @@
+// Public surface of the map renderer module.
+
+export {
+	DEFAULT_HIT_SLOP_PX,
+	KIND_ORDER,
+	DARK_THEME,
+	World,
+	type Camera,
+	type CirclePrim,
+	type LinePrim,
+	type PointPrim,
+	type Primitive,
+	type PrimitiveBase,
+	type PrimitiveID,
+	type PrimitiveKind,
+	type Style,
+	type Theme,
+	type Viewport,
+	type WrapMode,
+} from "./world";
+
+export {
+	clamp,
+	distSqPointToSegment,
+	screenToWorld,
+	torusShortestDelta,
+	worldToScreen,
+} from "./math";
+
+export {
+	clampCameraNoWrap,
+	minScaleNoWrap,
+	pivotZoom,
+} from "./no-wrap";
+
+export { hitTest, type Hit } from "./hit-test";
+
+export {
+	createRenderer,
+	type RendererHandle,
+	type RendererOptions,
+	type RendererPreference,
+} from "./render";
+
+export { sampleWorld } from "./fixtures";