infra: wire feature-cache-pvc into compile-and-train pipeline

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

infra/k8s/argo/compile-and-train-template.yaml

@@ -63,7 +63,7 @@ spec:
       - name: trades-data-dir
         value: /data/futures-baseline-trades
       - name: feature-cache-dir
-        value: /workspace/feature-cache
+        value: /feature-cache
       - name: tx-cost-bps
         value: "0.1"
       - name: tick-size
@@ -88,6 +88,9 @@ spec:
     - name: cargo-target-cuda
       persistentVolumeClaim:
         claimName: cargo-target-cuda
+    - name: feature-cache
+      persistentVolumeClaim:
+        claimName: feature-cache-pvc
 
   volumeClaimTemplates:
     - metadata:
@@ -302,17 +305,19 @@ spec:
               echo "ERROR: precompute_features not found in /workspace/bin/"
               exit 1
             fi
-            # Write to /workspace/ (writable emptyDir) — /data/ PVC is read-only
             $BINARY \
               --data-dir /data/futures-baseline \
               --mbp10-data-dir /data/futures-baseline-mbp10 \
               --trades-data-dir /data/futures-baseline-trades \
-              --output-dir /workspace/feature-cache \
+              --output-dir /feature-cache \
               --symbol ES.FUT \
               --yes
         volumeMounts:
           - name: training-data
             mountPath: /data
+            readOnly: true
+          - name: feature-cache
+            mountPath: /feature-cache
           - name: workspace
             mountPath: /workspace
         resources:
@@ -425,6 +430,8 @@ spec:
             value: ":4096:8"
           - name: CARGO_TARGET_DIR
             value: /workspace
+          - name: FOXHUNT_FEATURE_CACHE_DIR
+            value: "{{workflow.parameters.feature-cache-dir}}"
         args:
           - |
             set -e
@@ -441,10 +448,7 @@ spec:
 
             mkdir -p /workspace/output/hyperopt
 
-            # Feature cache auto-invalidates via content hash — no manual clearing needed.
-            # The cache key includes data paths + MBP-10 + trades dirs, so stale caches
-            # are automatically skipped when data changes.
-            echo "=== Feature cache: $(ls /workspace/.foxhunt_feature_cache/*.bin 2>/dev/null | wc -l) cached files ==="
+            echo "=== Feature cache: $(ls ${FOXHUNT_FEATURE_CACHE_DIR}/*.fxcache 2>/dev/null | wc -l) fxcache files ==="
 
             MODEL="{{workflow.parameters.model}}"
             case "$MODEL" in
@@ -492,6 +496,9 @@ spec:
           - name: training-data
             mountPath: /data
             readOnly: true
+          - name: feature-cache
+            mountPath: /feature-cache
+            readOnly: true
 
     # ── train-best: full training with best hyperparams ──
     - name: train-best
@@ -573,6 +580,9 @@ spec:
           - name: training-data
             mountPath: /data
             readOnly: true
+          - name: feature-cache
+            mountPath: /feature-cache
+            readOnly: true
 
     # ── evaluate: run evaluation on trained model ──
     - name: evaluate
@@ -637,6 +647,9 @@ spec:
           - name: training-data
             mountPath: /data
             readOnly: true
+          - name: feature-cache
+            mountPath: /feature-cache
+            readOnly: true
 
     # ── upload-results: push artifacts to GitLab packages ──
     - name: upload-results