fix: pass SHA via inputs.parameters in Argo DAG task arguments

Argo requires task output parameters to flow through DAG arguments →
template inputs, not direct {{tasks.X.outputs}} in container args.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

infra/k8s/argo/train-template.yaml

@@ -103,16 +103,32 @@ spec:
           - name: ensure-fxcache
             template: ensure-fxcache
             dependencies: [ensure-binary]
+            arguments:
+              parameters:
+                - name: sha
+                  value: "{{tasks.ensure-binary.outputs.parameters.sha}}"
           - name: hyperopt
             template: hyperopt
             dependencies: [ensure-binary, gpu-warmup, ensure-fxcache]
             when: "{{workflow.parameters.hyperopt-trials}} != 0"
+            arguments:
+              parameters:
+                - name: sha
+                  value: "{{tasks.ensure-binary.outputs.parameters.sha}}"
           - name: train-best
             template: train-best
             dependencies: [ensure-binary, gpu-warmup, ensure-fxcache, hyperopt]
+            arguments:
+              parameters:
+                - name: sha
+                  value: "{{tasks.ensure-binary.outputs.parameters.sha}}"
           - name: evaluate
             template: evaluate
             dependencies: [train-best]
+            arguments:
+              parameters:
+                - name: sha
+                  value: "{{tasks.ensure-binary.outputs.parameters.sha}}"
           - name: upload-results
             template: upload-results
             dependencies: [evaluate]
@@ -279,6 +295,9 @@ spec:
 
     # ── ensure-fxcache: precompute feature cache if needed ──
     - name: ensure-fxcache
+      inputs:
+        parameters:
+          - name: sha
       nodeSelector:
         k8s.scaleway.com/pool-name: ci-compile-cpu
       tolerations:
@@ -307,7 +326,7 @@ spec:
         args:
           - |
             set -e
-            SHA="{{tasks.ensure-binary.outputs.parameters.sha}}"
+            SHA="{{inputs.parameters.sha}}"
             BINARY="/data/bin/$SHA/precompute_features"
 
             if [ ! -x "$BINARY" ]; then
@@ -356,6 +375,9 @@ spec:
 
     # ── hyperopt: PSO/TPE hyperparameter optimization on GPU ──
     - name: hyperopt
+      inputs:
+        parameters:
+          - name: sha
       nodeSelector:
         k8s.scaleway.com/pool-name: "{{workflow.parameters.gpu-pool}}"
       tolerations:
@@ -399,7 +421,7 @@ spec:
         args:
           - |
             set -e
-            SHA="{{tasks.ensure-binary.outputs.parameters.sha}}"
+            SHA="{{inputs.parameters.sha}}"
             export PATH="/data/bin/$SHA:$PATH"
             export LD_LIBRARY_PATH=$(echo "$LD_LIBRARY_PATH" | tr ':' '\n' | grep -v stubs | tr '\n' ':' | sed 's/:$//')
             nvidia-smi
@@ -437,6 +459,9 @@ spec:
 
     # ── train-best: full training with best hyperparams ──
     - name: train-best
+      inputs:
+        parameters:
+          - name: sha
       nodeSelector:
         k8s.scaleway.com/pool-name: "{{workflow.parameters.gpu-pool}}"
       tolerations:
@@ -480,7 +505,7 @@ spec:
         args:
           - |
             set -e
-            SHA="{{tasks.ensure-binary.outputs.parameters.sha}}"
+            SHA="{{inputs.parameters.sha}}"
             export PATH="/data/bin/$SHA:$PATH"
             export LD_LIBRARY_PATH=$(echo "$LD_LIBRARY_PATH" | tr ':' '\n' | grep -v stubs | tr '\n' ':' | sed 's/:$//')
             nvidia-smi
@@ -520,6 +545,9 @@ spec:
 
     # ── evaluate: run evaluation on trained model ──
     - name: evaluate
+      inputs:
+        parameters:
+          - name: sha
       nodeSelector:
         k8s.scaleway.com/pool-name: "{{workflow.parameters.gpu-pool}}"
       tolerations:
@@ -559,7 +587,7 @@ spec:
         args:
           - |
             set -e
-            SHA="{{tasks.ensure-binary.outputs.parameters.sha}}"
+            SHA="{{inputs.parameters.sha}}"
             export PATH="/data/bin/$SHA:$PATH"
             export LD_LIBRARY_PATH=$(echo "$LD_LIBRARY_PATH" | tr ':' '\n' | grep -v stubs | tr '\n' ':' | sed 's/:$//')