ci: bump frontend test-shard memory to 2Gi (fix exit-137 OOM)

The 4 vitest shards were getting SIGKILL (exit code 137) because the
container memory limit was tighter than NODE_OPTIONS=--max-old-space-size=1024,
and 1024 wasn't enough headroom for the test workers either.

Set explicit kubernetes resources (request 1Gi / limit 2Gi) and bump
the V8 heap to 1.5Gi on install-frontend-deps and all 4 test shards.

Confirmed-by: pipeline 2081 step states (test-shard-1..4 all
state=failure exit_code=137; build/deploy steps then skipped).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

.woodpecker/frontend.yml

@@ -12,8 +12,15 @@ clone:
 steps:
   - name: install-frontend-deps
     image: node:24-alpine
+    backend_options:
+      kubernetes:
+        resources:
+          requests:
+            memory: 1Gi
+          limits:
+            memory: 2Gi
     environment:
-      NODE_OPTIONS: "--max-old-space-size=1024"
+      NODE_OPTIONS: "--max-old-space-size=1536"
     commands:
       - cd frontend && npm ci
 
@@ -21,8 +28,15 @@ steps:
     image: node:24-alpine
     depends_on:
       - install-frontend-deps
+    backend_options:
+      kubernetes:
+        resources:
+          requests:
+            memory: 1Gi
+          limits:
+            memory: 2Gi
     environment:
-      NODE_OPTIONS: "--max-old-space-size=1024"
+      NODE_OPTIONS: "--max-old-space-size=1536"
     commands:
       - cd frontend && npx vitest run --reporter=verbose --shard=1/4
 
@@ -30,8 +44,15 @@ steps:
     image: node:24-alpine
     depends_on:
       - install-frontend-deps
+    backend_options:
+      kubernetes:
+        resources:
+          requests:
+            memory: 1Gi
+          limits:
+            memory: 2Gi
     environment:
-      NODE_OPTIONS: "--max-old-space-size=1024"
+      NODE_OPTIONS: "--max-old-space-size=1536"
     commands:
       - cd frontend && npx vitest run --reporter=verbose --shard=2/4
 
@@ -39,8 +60,15 @@ steps:
     image: node:24-alpine
     depends_on:
       - install-frontend-deps
+    backend_options:
+      kubernetes:
+        resources:
+          requests:
+            memory: 1Gi
+          limits:
+            memory: 2Gi
     environment:
-      NODE_OPTIONS: "--max-old-space-size=1024"
+      NODE_OPTIONS: "--max-old-space-size=1536"
     commands:
       - cd frontend && npx vitest run --reporter=verbose --shard=3/4
 
@@ -48,8 +76,15 @@ steps:
     image: node:24-alpine
     depends_on:
       - install-frontend-deps
+    backend_options:
+      kubernetes:
+        resources:
+          requests:
+            memory: 1Gi
+          limits:
+            memory: 2Gi
     environment:
-      NODE_OPTIONS: "--max-old-space-size=1024"
+      NODE_OPTIONS: "--max-old-space-size=1536"
     commands:
       - cd frontend && npx vitest run --reporter=verbose --shard=4/4