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/docs/calc-bridge.md

@@ -63,6 +63,34 @@ outputs") is therefore intentionally not satisfied; the rewritten
 Phase 15 stage text records this decision and points back at this
 document.
 
+## Phase 16 waiver
+
+Phase 16 introduces ship-reach filtering for the cargo-route
+destination picker. The engine formula is trivial:
+
+```
+flightDistance = driveTech * 40
+```
+
+(`game/internal/model/game/race.go.FlightDistance`). The original
+Phase 16 stage text described surfacing this through `pkg/calc/`
+and `ui/core/calc/`; with the calc-bridge phase still deferred,
+implementing the bridge for one constant-time multiplication would
+be premature scaffolding. The picker therefore computes reach
+inline in TypeScript using
+`torusShortestDelta(planet.x, candidate.x, mapWidth)` and
+`Math.hypot` against `40 * report.localPlayerDrive`, where
+`localPlayerDrive` is decoded from the report's `Player` block by
+matching `Player.name` to `report.race`
+(`api/game-state.ts.findLocalPlayerDrive`).
+
+When the calc-bridge phase ships, the inline formula is replaced
+with a single call into the bridge: `calc.Reach(driveTech)` becomes
+the source of truth for both the picker and the cargo-route arrow
+auto-removal at turn cutoff. Until then, the UI duplicates
+`flightDistance` knowingly — same precedent as the production
+forecast deferral above.
+
 ## Planned bridge shape (follow-up phase)
 
 When the bridge phase lands, the contract should be: