feat(go): bundle the pro-engine binary and install it in the image

Vendors the prebuilt static engine binary (linux/amd64) at go/bin/swe-pro
and copies it to /usr/local/bin/swe-pro in the runtime image — the
supervisor's default path — so the published image is opt-in ready.
Runtime behavior is unchanged unless SWE_PRO_ENGINE is set.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: AbirAbbas

go/Dockerfile

@@ -146,6 +146,11 @@ RUN git config --global user.name "SWE-AF" && \
 COPY --from=builder /out/swe-planner /usr/local/bin/swe-planner
 COPY --from=builder /out/swe-fast /usr/local/bin/swe-fast
 
+# Prebuilt pro-engine binary (static, vendored at go/bin). Inert unless the
+# node is started with SWE_PRO_ENGINE=1 (see go/docs/pro-engine.md); the
+# supervisor's default SWE_PRO_BIN already points here.
+COPY go/bin/swe-pro /usr/local/bin/swe-pro
+
 # Pre-create /workspaces so named-volume mounts inherit correct permissions
 # (without this, Docker creates it as root read-only on fresh deployments).
 RUN mkdir -p /workspaces && chmod 777 /workspaces