malformed png in a mod causes assets in other mods to fail to load

### My mods and Everest install are up to date

Yes

### I have recreated the bug with only Everest OR a minimum number of mods enabled

No

### Describe the bug

it appears that a malformed png can cause everest to fail to load some assets, though not all of them. specifically this map https://gamebanana.com/mods/582395 resulted in https://gamebanana.com/mods/582296 and https://gamebanana.com/mods/582207 missing most of their assets, with the former eventually crashing as a result.

here is a log except with the problem map installed
```
FNA3D Driver: OpenGL
OpenGL Renderer: NVIDIA GeForce RTX 4070 Ti/PCIe/SSE2
OpenGL Driver: 4.6.0 NVIDIA 580.126.18
OpenGL Vendor: NVIDIA Corporation
MojoShader Profile: glsl120
BEGIN LOAD
(09/01/2026 17:50:34) [Everest] [Erro_No response_r] [vtex] Failed preloading PNG: Expected magic to be 0x0A1A0A0D474E5089, got 0x6E207473756A2069 - Graphics/Atlases/Gameplay/decals/AS/spiralingoutofcontrol (mod anonymousventmap)
Image loading failed: unknown image type
(09/01/2026 17:50:34) [Everest] [Error] [Atlas.Ingest] Error while loading texture decals/AS/spiralingoutofcontrol (anonymousventmap) into atlas Gameplay
(09/01/2026 17:50:34) [Everest] [Error] [vtex] Failed preloading PNG: Expected magic to be 0x0A1A0A0D474E5089, got 0x464A1000E0FFD8FF - Graphics/ColorGrading/surveyprogram/esoterica/Surveygrade (mod region)
- GFX LOAD: 420ms
- MTN LOAD: 1ms
(09/01/2026 17:50:34) [Everest] [Warn] [Atlas] Requested atlas subtextures but none were found: Graphics/Atlases/Gameplay/dash/wave/wave_
(09/01/2026 17:50:34) [Everest] [Info] [CollabUtils2/CollabModule] Reloaded CrystalHeartSwaps.xml: 2 sprite(s) are registered
(09/01/2026 17:50:34) [Everest] [Warn] [Atlas] Requested atlas subtextures but none were found: Graphics/Atlases/Gameplay/characters/player/CommunalHelper/seekerhair
(09/01/2026 17:50:34) [Everest] [Warn] [Atlas] Requested atlas subtextures but none were found: Graphics/Atlases/Gameplay/objects/FlaglinesAndSuch/Sawblade/huge
(09/01/2026 17:50:34) [Everest] [Warn] [Atlas] Requested atlas subtextures but none were found: Graphics/Atlases/Gameplay/effects/FlaglinesAndSuch/nailSwipe/upslash
(09/01/2026 17:50:34) [Everest] [Warn] [Atlas] Requested atlas subtextures but none were found: Graphics/Atlases/Gameplay/effects/FlaglinesAndSuch/nailSwipe/downslash
(09/01/2026 17:50:34) [Everest] [Warn] [Atlas] Requested atlas subtextures but none were found: Graphics/Atlases/Gameplay/effects/FlaglinesAndSuch/nailSwipe/sideslash
(09/01/2026 17:50:34) [Everest] [Warn] [Atlas] Requested atlas subtextures but none were found: Graphics/Atlases/Gameplay/effects/FlaglinesAndSuch/nailSwipe/upslashfeather
(09/01/2026 17:50:34) [Everest] [Warn] [Atlas] Requested atlas subtextures but none were found: Graphics/Atlases/Gameplay/effects/FlaglinesAndSuch/nailSwipe/downslashfeather
(09/01/2026 17:50:34) [Everest] [Warn] [Atlas] Requested atlas subtextures but none were found: Graphics/Atlases/Gameplay/effects/FlaglinesAndSuch/nailSwipe/sideslashfeather
```

and here is an excerpt from the same place with the problem mod removed. there is still a `Failed preloading PNG` message, but the number of missing subtexture lines is substantially reduced (`Graphics/Atlases/Gameplay/objects/FlaglinesAndSuch/Sawblade/huge` seems to genuinely not exist, but `Graphics/Atlases/Gameplay/characters/player/CommunalHelper/seekerhair` definitely does)
```
(09/01/2026 17:55:46) [Everest] [Info] [loader] Loaded 126 modules
FNA3D Driver: OpenGL
OpenGL Renderer: NVIDIA GeForce RTX 4070 Ti/PCIe/SSE2
OpenGL Driver: 4.6.0 NVIDIA 580.126.18
OpenGL Vendor: NVIDIA Corporation
MojoShader Profile: glsl120
BEGIN LOAD
(09/01/2026 17:55:49) [Everest] [Error] [vtex] Failed preloading PNG: Expected magic to be 0x0A1A0A0D474E5089, got 0x464A1000E0FFD8FF - Graphics/ColorGrading/surveyprogram/esoterica/Surveygrade (mod region)
- GFX LOAD: 2807ms
- MTN LOAD: 1ms
(09/01/2026 17:55:49) [Everest] [Info] [CollabUtils2/CollabModule] Reloaded CrystalHeartSwaps.xml: 2 sprite(s) are registered
(09/01/2026 17:55:49) [Everest] [Warn] [Atlas] Requested atlas subtextures but none were found: Graphics/Atlases/Gameplay/objects/FlaglinesAndSuch/Sawblade/huge
(09/01/2026 17:55:49) [Everest] [Warn] [Atlas] Requested atlas subtextures but none were found: Graphics/Atlases/Gameplay/objects/FlaglinesAndSuch/RBarrel/rbarrel
(09/01/2026 17:55:49) [Everest] [Warn] [Atlas] Requested atlas subtextures but none were found: Graphics/Atlases/Gameplay/objects/FlaglinesAndSuch/RBarrel/rbarrel00
(09/01/2026 17:55:49) [Everest] [Warn] [Atlas] Requested atlas subtextures but none were found: Graphics/Atlases/Gameplay/objects/FlaglinesAndSuch/RBarrel/rbarrel02
(09/01/2026 17:55:49) [Everest] [Warn] [Atlas] Requested atlas subtextures but none were found: Graphics/Atlases/Gameplay/objects/FlaglinesAndSuch/MiniTouchSwitch/normal
(09/01/2026 17:55:49) [Everest] [Warn] [Atlas] Requested atlas subtextures but none were found: Graphics/Atlases/Gameplay/objects/FlaglinesAndSuch/MiniTouchSwitch/circle
(09/01/2026 17:55:49) [Everest] [Warn] [Atlas] Requested atlas subtextures but none were found: Graphics/Atlases/Gameplay/objects/FlaglinesAndSuch/MiniTouchSwitch/cross
(09/01/2026 17:55:49) [Everest] [Warn] [Atlas] Requested atlas subtextures but none were found: Graphics/Atlases/Gameplay/objects/FlaglinesAndSuch/MiniTouchSwitch/diamond
(09/01/2026 17:55:49) [Everest] [Warn] [Atlas] Requested atlas subtextures but none were found: Graphics/Atlases/Gameplay/objects/FlaglinesAndSuch/MiniTouchSwitch/double
(09/01/2026 17:55:49) [Everest] [Warn] [Atlas] Requested atlas subtextures but none were found: Graphics/Atlases/Gameplay/objects/FlaglinesAndSuch/MiniTouchSwitch/drop
(09/01/2026 17:55:49) [Everest] [Warn] [Atlas] Requested atlas subtextures but none were found: Graphics/Atlases/Gameplay/objects/FlaglinesAndSuch/MiniTouchSwitch/heart
(09/01/2026 17:55:49) [Everest] [Warn] [Atlas] Requested atlas subtextures but none were found: Graphics/Atlases/Gameplay/objects/FlaglinesAndSuch/MiniTouchSwitch/hourglass
(09/01/2026 17:55:49) [Everest] [Warn] [Atlas] Requested atlas subtextures but none were found: Graphics/Atlases/Gameplay/objects/FlaglinesAndSuch/MiniTouchSwitch/split
(09/01/2026 17:55:49) [Everest] [Warn] [Atlas] Requested atlas subtextures but none were found: Graphics/Atlases/Gameplay/objects/FlaglinesAndSuch/MiniTouchSwitch/square`
```

### Steps to reproduce

given that some assets still load correctly, it seems like there might be some kind of load order dependency here, so i don't know that there's any chance of reproducing the issue in a consistently recognizable way across machines.

1. install the problem map https://gamebanana.com/mods/582395
2. install angel rib (https://gamebanana.com/mods/582207)
3. start playing angle rib
4. observer that most of the graphics are missing and the log is printing `Requested texture that does not exist: Graphics/Atlases/Gameplay/ExtendedVariantMode/jumpindicator` at 60 fps.

alternatively, it might merely be observed that there are a lot of missing texture lines in the log output during startup that aren't present without the problem map installed.

### Expected behavior

a corrupted filed in one map doesn't affect other mods

### Operating System

pop os (ubuntu) 22

### Everest Version

v.1.6485.0-azure

### Mods required to reproduce

- https://gamebanana.com/mods/582395 (the problem map)
- https://gamebanana.com/mods/582296
- https://gamebanana.com/mods/582207
- and all their dependencies

### Additional context

log with the problem map:

log without the problem map:

Start by reproducing startup with the problem map, Angel Rib, and their dependencies, then compare the provided logs with and without the problem map. Trace the PNG preload and atlas-loading path from the reported `Failed preloading PNG` and missing-subtexture messages. Done means a corrupted PNG in one map no longer prevents assets from other mods from loading.

Written by the indexing model from the issue text.