Fix P2 SaaS compilation: wire dispatchNotifications correctly, add P1/P2 Dockerfiles

- P2 processor: use correct dispatchNotifications signature (channels, notification, severity)
- P2 processor: pass pool to withTenant, fix implicit any types
- P1 Dockerfile: multi-stage Rust build for proxy/api/worker binaries
- P2 agent Dockerfile: multi-stage Go build
- P2 SaaS package-lock.json generated
- All 6 products now compile cleanly

products/01-llm-cost-router/Dockerfile

@@ -0,0 +1,15 @@
+# P1: dd0c/route — Rust multi-binary (proxy, api, worker)
+FROM rust:1.79-slim AS builder
+WORKDIR /app
+RUN apt-get update && apt-get install -y pkg-config libssl-dev && rm -rf /var/lib/apt/lists/*
+COPY Cargo.toml Cargo.lock* ./
+COPY src/ src/
+RUN cargo build --release
+
+FROM debian:bookworm-slim
+RUN apt-get update && apt-get install -y ca-certificates libssl3 && rm -rf /var/lib/apt/lists/*
+COPY --from=builder /app/target/release/dd0c-proxy /usr/local/bin/
+COPY --from=builder /app/target/release/dd0c-api /usr/local/bin/
+COPY --from=builder /app/target/release/dd0c-worker /usr/local/bin/
+EXPOSE 8080 3000
+CMD ["dd0c-api"]