feat: add Dockerfile for app to deploy preview

app/Dockerfile

@@ -0,0 +1,70 @@
+# --- Builder Stage ---
+FROM node:24-alpine AS builder
+
+# Install system dependencies
+RUN apk add --no-cache curl g++ gcc make libc-dev
+
+# Optimized Rust Installation
+ENV RUSTUP_HOME=/usr/local/rustup \
+  CARGO_HOME=/usr/local/cargo \
+  PATH=/usr/local/cargo/bin:$PATH
+
+RUN curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y --no-modify-path --profile minimal \
+  && rustup target add wasm32-unknown-unknown
+
+WORKDIR /app
+
+# 1. Copy Manifests for Caching
+# Copy root manifests
+COPY pnpm-lock.yaml pnpm-workspace.yaml package.json Cargo.lock Cargo.toml ./
+
+# Copy all sub-package package.json and Cargo.toml files to cache dependency installation
+# This "wildcard" approach in Alpine/sh can be tricky, so we copy the specific directories 
+# that define the workspace structure.
+COPY packages/ ./packages/
+COPY nodes/ ./nodes/
+COPY app/package.json ./app/
+
+# 2. Install & Cache Dependencies
+# We mount the Cargo registry (crates) and the target folder (compiled artifacts)
+RUN --mount=type=cache,id=pnpm-store,target=/root/.local/share/pnpm/store \
+  --mount=type=cache,target=/usr/local/cargo/registry \
+  --mount=type=cache,target=/app/target \
+  npm install -g pnpm@latest && \
+  pnpm install --frozen-lockfile
+
+# 3. Full Source Copy & Build
+COPY . .
+
+# We apply the cache mounts again during the build. 
+# pnpm build:nodes will now find its Rust artifacts in /app/target from the previous run.
+RUN --mount=type=cache,id=pnpm-store,target=/root/.local/share/pnpm/store \
+  --mount=type=cache,target=/usr/local/cargo/registry \
+  --mount=type=cache,target=/app/target \
+  pnpm build:nodes && \
+  pnpm --filter @nodarium/app... build
+
+# --- Static Runner Stage ---
+FROM nginx:alpine AS runner
+
+# Remove default nginx config
+RUN rm /etc/nginx/conf.d/default.conf
+
+# Minimal static file config
+COPY <<EOF /etc/nginx/conf.d/app.conf
+server {
+    listen 80;
+    server_name _;
+    root /app;
+    index index.html;
+
+    location / {
+        try_files \$uri \$uri/ /index.html;
+    }
+}
+EOF
+
+# Copy built files
+COPY --from=builder /app/app/build /app
+
+EXPOSE 80