fix: update Dockerfile.test to use bun instead of pnpm

Dockerfile.test

@@ -14,6 +14,9 @@ FROM node:22-bookworm-slim
 
 # ── System dependencies (identical to production) ────────────────────────────
 RUN apt-get update && apt-get install -y --no-install-recommends \
+    ca-certificates \
+    curl \
+    unzip \
     ffmpeg \
     chromium \
     libgbm1 \
@@ -57,13 +60,18 @@ RUN npx --yes @puppeteer/browsers install chrome-headless-shell@stable \
 
 WORKDIR /app
 
+# Install bun
+RUN curl -fsSL https://bun.sh/install | bash
+ENV PATH="/root/.bun/bin:$PATH"
+
 # Install dependencies (full, including devDependencies for tsx + test harness)
-COPY pnpm-workspace.yaml package.json pnpm-lock.yaml ./
+COPY package.json bun.lock pnpm-workspace.yaml ./
 COPY packages/core/package.json packages/core/package.json
 COPY packages/engine/package.json packages/engine/package.json
 COPY packages/producer/package.json packages/producer/package.json
-RUN corepack enable && corepack prepare pnpm@10 --activate \
-    && pnpm install --frozen-lockfile
+COPY packages/cli/package.json packages/cli/package.json
+COPY packages/studio/package.json packages/studio/package.json
+RUN bun install --frozen-lockfile
 
 # Copy source
 COPY packages/core/ packages/core/
@@ -71,8 +79,8 @@ COPY packages/engine/ packages/engine/
 COPY packages/producer/ packages/producer/
 
 # Build core runtime artifacts (needed by renderer)
-RUN pnpm --filter @hyperframes/core build:hyperframes-runtime:modular
+RUN bun run --filter @hyperframes/core build:hyperframes-runtime:modular
 
 WORKDIR /app/packages/producer
 
-ENTRYPOINT ["pnpm", "exec", "tsx", "src/regression-harness.ts", "--", "--sequential"]
+ENTRYPOINT ["bunx", "tsx", "src/regression-harness.ts", "--", "--sequential"]