v0.1.5 - Fix brush binary name

Fixes

• Dockerfile: brush-cli is a library-only crate — it produces no binary. The actual executable is the [[bin]] target in brush-app named brush (src/bin.rs), so the correct path is target/release/brush.
• Dockerfile: use cargo build --release -p brush-app --bin brush to build only the desktop binary, skipping the cdylib/rlib targets.
• scripts/pipeline.py: update local dev fallback paths and error message to reference target/release/brush.