feat(client): highlight small players with a pulsing glow (#4525)

## Description:

Adds a **"Highlight small players"** client setting (in the in-game
Settings menu). When it's on, human players holding **0.2% or less of
the map** get a soft red glow that breathes (a pulsing aura) around
their territory, starting **one minute into the game**. This makes
near-eliminated players easy to spot on a busy map, even when their
territory is scattered in fragments or sitting under structures.

How it works:

- **Purely client-side**, no simulation or determinism impact.
`SmallPlayerGlowPass` renders a tile-space bloom: extract a sub-tile
mask of the small players' tiles, run a separable Gaussian blur, then
composite the soft aura over the map additively. It's camera-independent
(no shimmer when panning/zooming), so scattered tiles blur into one
clean halo. The aura breathes: its intensity fades fully to 0 at the
trough for clear contrast.
- The set is recomputed each tick in `WebGLFrameBuilder`: alive human
players with `tilesOwned / (landTiles - fallout) <= 0.002` (0.2%),
suppressed during the spawn phase and the first minute.
- Backed by a persisted `UserSettings` flag, toggleable live from the
in-game Settings modal (with a new, distinct icon).
- Drawn after the structure passes so buildings can't hide it.
- Mirrors the existing FalloutBloom pipeline and reuses the shared blur
shader and render-target helpers rather than duplicating them. Tunable
via `render-settings.json` (`smallPlayerGlow`: color / alpha /
pulseSpeed).

UI (glow fades in and out):
<img width="474" height="334" alt="image"
src="https://github.com/user-attachments/assets/2b94f292-2cbb-43d3-82fb-f274d1afdedf"
/>
<img width="976" height="400" alt="image"
src="https://github.com/user-attachments/assets/f1b972d7-e046-4f7a-ab43-da1eb758c7b5"
/>


## Please complete the following:

- [x] I have added screenshots for all UI updates
- [x] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [x] I have added relevant tests to the test directory

## Please put your Discord username so you can be contacted if a bug or
regression is found:

zixer._

resources/images/HighlightIconWhite.svg

@@ -0,0 +1,5 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none" stroke="#fefffe" stroke-width="2">
+  <circle cx="12" cy="12" r="2.5" fill="#fefffe" stroke="none" />
+  <circle cx="12" cy="12" r="6" />
+  <circle cx="12" cy="12" r="10" opacity="0.45" />
+</svg>

resources/lang/en.json

@@ -1488,6 +1488,8 @@
     "ground_attack_desc": "Send a ground attack to the tile under your cursor.",
     "help_messages_desc": "Show contextual tips and warnings during gameplay, such as army limit warnings and general gameplay advice.",
     "help_messages_label": "Help Messages",
+    "highlight_small_players_desc": "Add a glow to small players so they're easy to find.",
+    "highlight_small_players_label": "Highlight small players",
     "keybind_conflict_error": "The key {key} is already bound to another action.",
     "keybinds_hint": "Click a key to rebind it. You can assign a single key or Shift + key combination.",
     "left_click_desc": "When ON, left-click opens menu and sword button attacks. When OFF, left-click attacks directly.",