fix(CRITICAL): engine death on image request + stop overwriting base corex modules

Root cause from latest docker build log:
  ValueError: You set image=0 in --limit-mm-per-prompt, but found 1 items
  → Engine background task crashes → AsyncEngineDeadError → all subsequent 503

Fixes:
1. computility-run.yaml: add --limit-mm-per-prompt image=1
   Prevents multimodal ValueError from killing the engine process.

2. patch_ops.sh: DON'T overwrite base image's corex_gdn.py/corex_moe.py
   Comp 168 log proves base image's corex modules work with libcorex_gdn.so.
   Our overwrite broke CoreXGDN.__init__ (unexpected kwarg 'num_v_heads').
   Only deploy ours if base has NO corex modules at all.
   Also deploy corex_fa2.py if base lacks it.

3. qwen3_5.py: try multiple CoreXGDN init signatures
   Base image CoreXGDN may accept different kwargs than ours.
   Try kwargs form first, fall back to positional.

4. corex_gdn.py: accept both calling conventions in __init__
   Future-proof for when we DO need to deploy ours.

5. Copied upstream_ref headers: ilu_layer_fused_moe.h, ilu_layer_attention.h
   Last 2 missing ILU files from xllm. All 14/14 now present.

computility-run.yaml

@@ -32,6 +32,8 @@ command:
     - '8192'
     - --dtype
     - half
+    - --limit-mm-per-prompt
+    - image=1
 env:
     - name: VLLM_ENGINE_ITERATION_TIMEOUT_S
       value: '3600'