Add physics/combat foundation, resource pickup flow, VFX polish, and HUD

- Cannon-es colliders for map/props/breakable crates (BreakablePropC,
  PhysicsC), AoE bat combat with facing-cone gating (PlayerC), camera
  follow with obstacle avoidance and facing-lock look-ahead
  (CameraFollowC).
- Resource pickups: scatter/bounce/hit-flash/sparkle-burst lifecycle with
  pooled sparkle VFX (ResourceC, SparkleFxC), flying to a screen-projected
  HUD anchor and on into the Pay Zone with perspective-corrected sizing
  (HudC, PayZoneC).
- Designer VFX playback via three.quarks for crate hit/destroy
  (PropVfxC), plus a procedural weapon-swing trail (WeaponTrailC).
- Resource-counter HUD UI (ui.css, images.ts) with CSS-driven mount/bump
  animations.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/css/ui.css

@@ -2,3 +2,101 @@
   /* flex-basis: 60%; */
   flex-grow: 1;
 }
+
+/* HudC — resource counter plate (dark background + diagonal wood-plank
+   icon baked into resourceCounterBgSrc, see images.ts/temp/Tool_15.webp).
+   184x71 source aspect ratio (~2.59:1) — aspect-ratio below derives height
+   from width automatically, so the two can never drift out of sync the way
+   two independently-tuned vh values could if only one got changed later.
+   background-image itself is set from HudC.ts (the asset path/base64 is
+   only known at runtime via the build's asset pipeline), everything else
+   lives here.
+
+   Split into two elements on purpose: .resource-hud only positions/sizes
+   and plays the one-shot mount animation; .resource-hud__plate (background
+   + number together) is what the update-bump animates. Doing both on the
+   same element would fight each other — toggling a class that swaps
+   .resource-hud's own `animation-name` away from resource-hud-enter and
+   back again makes the browser replay resource-hud-enter every time
+   (a value change, even back to the same value, restarts a CSS animation),
+   so every resource pickup would re-trigger the fade/slide-in on top of
+   the bump. Two elements means two independent animation lifecycles. */
+.resource-hud {
+  /* Single source of truth for the plate's scale — width below and the
+     count's font-size (see .resource-hud__count) both derive from this one
+     value, so resizing the whole HUD is a one-line change instead of
+     hunting down every place a size was independently tuned in vh. */
+  --hud-width: 9vh;
+  position: absolute;
+  top: 6%;
+  right: 10%;
+  width: var(--hud-width);
+  aspect-ratio: 184 / 71;
+  pointer-events: none;
+  z-index: 50;
+  /* Runs once as soon as the element mounts — no JS timing/opacity code
+     needed, the browser drives it (Day 8: "use built-in animations instead
+     of changing elements through code"). */
+  animation: resource-hud-enter 400ms ease-out;
+}
+
+@keyframes resource-hud-enter {
+  from {
+    opacity: 0;
+    transform: translateX(1.5rem);
+  }
+  to {
+    opacity: 1;
+    transform: translateX(0);
+  }
+}
+
+.resource-hud__plate {
+  position: relative;
+  width: 100%;
+  height: 100%;
+  background-repeat: no-repeat;
+  background-size: 100% 100%;
+}
+
+/* Toggled by HudC whenever the displayed number actually changes — a pure
+   CSS "pop" of the whole plate (background + number together), not a
+   JS-driven tween (Day 8 technical note) and not just the digit (see
+   chat: "не тільки на каунтер"). HudC removes and re-adds this class
+   (forcing a reflow in between) each time, which is what lets the
+   animation restart cleanly even if it retriggers before the previous run
+   finished — e.g. PayZoneC draining one resource every 0.3s while the
+   player stands in the zone. */
+.resource-hud__plate.is-bumping {
+  animation: resource-hud-bump 220ms ease-out;
+}
+
+@keyframes resource-hud-bump {
+  0% {
+    transform: scale(1);
+  }
+  40% {
+    transform: scale(1.18);
+  }
+  100% {
+    transform: scale(1);
+  }
+}
+
+.resource-hud__count {
+  position: absolute;
+  left: 16%;
+  top: 46%;
+  width: 46%;
+  transform: translateY(-50%);
+  text-align: center;
+  color: #ffffff;
+  font-weight: bold;
+  /* Scales with --hud-width (set on .resource-hud, inherited down through
+     .resource-hud__plate) instead of a fixed vh value, so it tracks
+     whatever the plate is currently sized to — ratio matches the 2.1vh
+     that read well at the original 12vh plate width (2.1/12 ≈ 0.175). */
+  font-size: calc(var(--hud-width) * 0.175);
+  font-family: gameFont, sans-serif;
+  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.8);
+}