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/player.anm2

@@ -58,6 +58,20 @@
         }
       ]
     },
+    "Preview": {
+      "length": 16,
+      "layers": [
+        {
+          "layer": 0,
+          "frames": [
+            {"region": 1, "scale": [-100, 100], "delay": 4, "interpolation": "linear"},
+            {"region": 2, "scale": [-100, 100], "delay": 4, "interpolation": "linear"},
+            {"region": 3, "scale": [-100, 100], "delay": 4, "interpolation": "linear"},
+            {"region": 4, "scale": [-100, 100], "delay": 4, "interpolation": "linear"}
+          ]
+        }
+      ]
+    },
     "Jump": {"layers": [{"layer": 0, "frames": [{"region": 5}]}]},
     "Fall": {"layers": [{"layer": 0, "frames": [{"region": 6}]}]},
     "Slide": {"layers": [{"layer": 0, "frames": [{"region": 7}]}]},