HUD pass, weapon and trinket rework, and font arrows

HUD:
- Hotbars fit a quarter of the screen, dropping to small then tiny slots
  (thinner outlines when tiny), with cooldown bars matching their size.
- HUD elements are drawn on their own layer and composited at one
  opacity: hotbar slots are see-through until hovered, the rest fade
  while hovered.
- Rival windows fit the right column in at most two rows, shrinking
  icons then font, then dropping icons for name, health and ping bars.
- Tooltips number equipped items' slots and say Recoil for weapons that
  only push back. Previews use arrows, spread uses degrees.
- Crosshair fills in and shakes with charge, and weapons shake after
  firing until their cooldown ends. DPS and speed meters off by default.

Gameplay:
- Dual Wield stacks: each copy fires another recently held weapon from
  a fanned off-hand, at its own level's cut.
- Flamethrower: no slowing, smaller fireball with some recoil, and an
  airblast that knocks others away.
- Iron Weights slam on any landing faster than a plain fall (platforms
  too), stacking radius and damage, and speeding fast falls.
- Stuck arrows are one-way ledges until they fade, matching their
  (slightly larger) hit size. Attacks now collide with slopes.
- Halved Tesla Coil, Recoil Coil, Diazepam, Shock Absorber, Feather and
  screenshake values.

Art and tools:
- Weapon and trinket icons merged into one sheet each (normal, small,
  tiny), cells in catalog order. Grimoire wisps stand upright.
- Fonts gain the degree sign and four arrows, decoded from UTF-8.
- Menu fighter preview walks at quarter speed.
- Unequip from either catalog tab by right click or gamepad.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

resources/gfx/ui.anm2

@@ -7,7 +7,9 @@
       "regions": [
         {"name": "Chevron", "crop": [4, 5], "size": [7, 5], "pivot": [7, 5]},
         {"name": "Arrow", "crop": [4, 5], "size": [7, 5], "origin": "center"},
-        {"name": "Crosshair", "crop": [17, 1], "size": [13, 13], "pivot": [6, 6]}
+        {"name": "Crosshair", "crop": [17, 1], "size": [13, 13], "pivot": [6, 6]},
+        {"name": "Chevron Small", "crop": [1, 11], "size": [5, 4], "pivot": [5, 4]},
+        {"name": "Chevron Tiny", "crop": [8, 11], "size": [3, 3], "pivot": [1, 3]}
       ]
     }
   ],
@@ -16,38 +18,10 @@
   ],
   "defaultAnimation": "Chevron",
   "animations": {
-    "Chevron": {
-      "length": 1,
-      "layers": [
-        {
-          "layer": 0,
-          "frames": [
-            {"region": 0}
-          ]
-        }
-      ]
-    },
-    "Arrow": {
-      "length": 1,
-      "layers": [
-        {
-          "layer": 0,
-          "frames": [
-            {"region": 1}
-          ]
-        }
-      ]
-    },
-    "Crosshair": {
-      "length": 1,
-      "layers": [
-        {
-          "layer": 0,
-          "frames": [
-            {"region": 2}
-          ]
-        }
-      ]
-    }
+    "Chevron": {"layers": [{"layer": 0, "frames": [{"region": 0}]}]},
+    "Arrow": {"layers": [{"layer": 0, "frames": [{"region": 1}]}]},
+    "Crosshair": {"layers": [{"layer": 0, "frames": [{"region": 2}]}]},
+    "Chevron Small": {"layers": [{"layer": 0, "frames": [{"region": 3}]}]},
+    "Chevron Tiny": {"layers": [{"layer": 0, "frames": [{"region": 4}]}]}
   }
 }