fix: sqlx offline cache + borrow fix + Dockerfile + unified CI

- Add .sqlx/ query cache (generated from live DB)
- SQLX_OFFLINE=true in Dockerfile (no DB at build time)
- Fix borrow checker errors in versioning.rs (ref from)
- rust:1.81 → rust:1-bookworm
- cargo build --release -p mem-cli
- Single CI job, DOCKER_HOST, build+push on all events

Dockerfile

@@ -1,15 +1,16 @@
 # Multi-stage build for Poimen Memory Service (Rust)
 
 # Stage 1: Builder
-FROM rust:1.81-bookworm as builder
+FROM rust:1-bookworm as builder
 
 WORKDIR /build
 
 # Copy source
 COPY . .
 
-# Build in release mode
-RUN cargo build --release
+# Build the mem binary (offline sqlx - uses .sqlx/ cache)
+ENV SQLX_OFFLINE=true
+RUN cargo build --release -p mem-cli
 
 # Stage 2: Runtime
 FROM debian:bookworm-slim