ui/phase-16: cargo routes inspector + map pick foundation

Add per-planet cargo routes (COL/CAP/MAT/EMP) to the inspector with
a renderer-driven destination picker (faded out-of-reach planets,
cursor-line anchor, hover-highlight) and per-route arrows on the
map. The pick-mode primitives are exposed via `MapPickService` so
ship-group dispatch in Phase 19/20 can reuse the same surface.

Pass A — generic map foundation:
- hit-test now sizes the click zone to `pointRadiusPx + slopPx` so
  the visible disc is always part of the target.
- `RendererHandle` gains `onPointerMove`, `onHoverChange`,
  `setPickMode`, `getPickState`, `getPrimitiveAlpha`,
  `setExtraPrimitives`, `getPrimitives`. The click dispatcher is
  centralised: pick-mode swallows clicks atomically so the standard
  selection consumers do not race against teardown.
- `MapPickService` (`lib/map-pick.svelte.ts`) wraps the renderer
  contract in a promise-shaped `pick(...)`. The in-game shell
  layout owns the service so sidebar and bottom-sheet inspectors
  see the same instance.
- Debug-surface registry exposes `getMapPrimitives`,
  `getMapPickState`, `getMapCamera` to e2e specs without spawning a
  separate debug page after navigation.

Pass B — cargo-route feature:
- `CargoLoadType`, `setCargoRoute`, `removeCargoRoute` typed
  variants with `(source, loadType)` collapse rule on the order
  draft; round-trip through the FBS encoder/decoder.
- `GameReport` decodes `routes` and the local player's drive tech
  for the inline reach formula (40 × drive). `applyOrderOverlay`
  upserts/drops route entries for valid/submitting/applied
  commands.
- `lib/inspectors/planet/cargo-routes.svelte` renders the
  four-slot section. `Add` / `Edit` call `MapPickService.pick`,
  `Remove` emits `removeCargoRoute`.
- `map/cargo-routes.ts` builds shaft + arrowhead primitives per
  cargo type; the map view pushes them through
  `setExtraPrimitives` so the renderer never re-inits Pixi on
  route mutations (Pixi 8 doesn't support that on a reused
  canvas).

Docs:
- `docs/cargo-routes-ux.md` covers engine semantics + UI map.
- `docs/renderer.md` documents pick mode and the debug surface.
- `docs/calc-bridge.md` records the Phase 16 reach waiver.
- `PLAN.md` rewrites Phase 16 to reflect the foundation + feature
  split and the decisions baked in (map-driven picker, inline
  reach, optimistic overlay via `setExtraPrimitives`).

Tests:
- `tests/map-pick-mode.test.ts` — pure overlay-spec helper.
- `tests/map-cargo-routes.test.ts` — `buildCargoRouteLines`.
- `tests/inspector-planet-cargo-routes.test.ts` — slot rendering,
  picker invocation, collapse, cancel, remove.
- Extensions to `order-draft`, `submit`, `order-load`,
  `order-overlay`, `state-binding`, `inspector-planet`,
  `inspector-overlay`, `game-shell-sidebar`, `game-shell-header`.
- `tests/e2e/cargo-routes.spec.ts` — Playwright happy path: add
  COL, add CAP, remove COL, asserting both the inspector and the
  arrow count via `__galaxyDebug.getMapPrimitives()`.

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

ui/frontend/src/lib/inspectors/planet.svelte

@@ -16,6 +16,7 @@ field with five buttons.
 	import { getContext, tick } from "svelte";
 	import type {
 		ReportPlanet,
+		ReportRoute,
 		ShipClassSummary,
 	} from "../../api/game-state";
 	import { i18n, type TranslationKey } from "$lib/i18n/index.svelte";
@@ -27,13 +28,27 @@ field with five buttons.
 		validateEntityName,
 		type EntityNameInvalidReason,
 	} from "$lib/util/entity-name";
+	import CargoRoutes from "./planet/cargo-routes.svelte";
 	import Production from "./planet/production.svelte";
 
 	type Props = {
 		planet: ReportPlanet;
 		localShipClass: ShipClassSummary[];
+		routes: ReportRoute[];
+		planets: ReportPlanet[];
+		mapWidth: number;
+		mapHeight: number;
+		localPlayerDrive: number;
 	};
-	let { planet, localShipClass }: Props = $props();
+	let {
+		planet,
+		localShipClass,
+		routes,
+		planets,
+		mapWidth,
+		mapHeight,
+		localPlayerDrive,
+	}: Props = $props();
 
 	const kindKeyMap: Record<ReportPlanet["kind"], TranslationKey> = {
 		local: "game.inspector.planet.kind.local",
@@ -198,6 +213,14 @@ field with five buttons.
 
 	{#if planet.kind === "local"}
 		<Production {planet} {localShipClass} />
+		<CargoRoutes
+			{planet}
+			{routes}
+			{planets}
+			{mapWidth}
+			{mapHeight}
+			{localPlayerDrive}
+		/>
 	{/if}
 
 	<dl class="fields">