feat(ui): F8-12 — map polish (zoom invariance, labels, selection, soft radius) (#55)

* Honest pixel-space sizing for `pointRadiusPx` / `strokeWidthPx`: the
  renderer divides by the current camera scale on every
  `viewport.zoomed` so thin lines / small markers stay the same on-screen
  size at any zoom.
* Known-size planets switch to `pointRadiusWorld`, softened against the
  reference scale by `PLANET_SIZE_ZOOM_ALPHA = 0.33`; unidentified
  planets pin to a 3-px disc.
* New planet label layer renders a two-line `name / #N` legend under
  each planet (`#N` only for unidentified or when the new `planetNames`
  toggle is off). Selection now paints an inverse-fill frame around the
  selected planet's label plus an outline on the disc; the old
  selection-ring primitive is retired.
* Bombing markers swap the separate CirclePrim for a planet-outline
  overlay (damaged / wiped colour); the report deep-link moves to a
  "view bombing report" link in the planet inspector.
* Docs + tests follow: `renderer.md` reflects the new sizing contract +
  label / outline layers, vitest covers the sizing math, label
  formatting, and the new toggle, and the map-toggles e2e adds a
  persistence case for `planetNames`.

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

ui/docs/renderer.md

@@ -66,13 +66,48 @@ interface LinePrim   extends PrimitiveBase { kind: 'line';
 
 `radius` is in world units. `style.strokeWidthPx` and
 `style.pointRadiusPx` are in screen pixels and stay constant under
-zoom (Pixi's stroke width is in pixel space when the parent
-container is scaled).
+zoom — F8-12 / #28 wired the renderer to repaint every affected
+`Graphics` on every `viewport.zoomed` event with
+`size_in_world = size_in_pixels / cameraScale`. `displayStrokeWidthWorld`
+and `displayPointRadiusWorld` (in `src/map/world.ts`) compute those
+world-space values; the hit-test reads the same helpers so the click
+zone always matches the visible footprint.
+
+`style.pointRadiusWorld` is the alternative sizing rule for planet
+discs with a known `size`: the renderer treats the base radius as
+world units and softens its growth with the camera scale through
+`PLANET_SIZE_ZOOM_ALPHA` (0.33). At `scale = scaleRef` (the
+"whole world fits the viewport" zoom) the visible radius equals the
+base radius; zooming in grows it sub-linearly so on-screen pixel
+size scales as `scale^α`. Setting both `pointRadiusWorld` and
+`pointRadiusPx` ignores the pixel-space field.
 
 Default hit slop in screen pixels: point=8, circle=6, line=6.
 These are touch-ergonomic defaults; per-primitive `hitSlopPx > 0`
 overrides them.
 
+### Planet label layer
+
+Independent of the primitive stream, the renderer mounts a per-copy
+`labelLayer` (F8-12 / #29). `RendererHandle.setPlanetLabels(labels,
+selectedPlanetId)` replaces the dataset; the renderer keeps each
+label container at `(planet.x, planet.y + visibleRadius + gapPx)`
+and at `scale = 1 / cameraScale` so the text reads at the same
+pixel size regardless of zoom. The selected planet gets an
+inverse-fill frame around its label, replacing the retired
+`selection-ring` primitive (F8-12 / #30).
+
+### Planet outline overlay
+
+`RendererHandle.setPlanetOutlines(outlines)` paints a thin stroke
+around the visible disc of any planet number listed in the spec.
+The map view feeds it the union of bombings (damaged / wiped accent
+colour, gated by the `bombingMarkers` toggle) and the current
+selection (`selectionAccent` colour); selection wins on the same
+planet. The radius follows `displayPointRadiusWorld`, so the
+outline hugs the disc through every zoom step — softened or
+pixel-space alike.
+
 ## Theme
 
 A `Theme` is the renderer's full colour palette: the canvas background
@@ -127,11 +162,15 @@ target.
 
 Per-primitive distance:
 
-- **Point**: `distSq ≤ (pointRadiusPx + slopWorld)²`. The visible
-  disc is part of the click target — a click on any pixel of the
-  rendered planet registers as a hit, with `slopWorld` adding a
-  small ergonomic margin on top. `pointRadiusPx` defaults to
-  `DEFAULT_POINT_RADIUS_PX = 3` when unset.
+- **Point**: `distSq ≤ (visibleRadiusWorld + slopWorld)²`. The
+  visible disc is part of the click target — a click on any pixel of
+  the rendered planet registers as a hit, with `slopWorld` adding a
+  small ergonomic margin on top. `visibleRadiusWorld` comes from
+  `displayPointRadiusWorld` (F8-12 / #28 + #31): pixel-space
+  `pointRadiusPx / scale` for unidentified planets and most ship
+  groups, softened-by-zoom `pointRadiusWorld * (scale / scaleRef)^(α-1)`
+  for planets with a known `size`. `pointRadiusPx` defaults to
+  `DEFAULT_POINT_RADIUS_PX = 3` when neither field is set.
 - **Filled circle**: `distSq ≤ (radius + slopWorld)²` where
   `radius` is in world units. The circle counts as filled when
   `style.fillColor` is set and `style.fillAlpha > 0`.