ci(sync-pr): allow custom command & secure git remote auth with token

Author: oleander

Dockerfile

@@ -43,6 +43,7 @@ WORKDIR /app
 ARG GH_TOKEN
 ENV GH_TOKEN=$GH_TOKEN
 RUN gh repo clone oleander/git-ai /app
+RUN git remote set-url origin https://x-access-token:$GH_TOKEN@github.com/oleander/git-ai.git
 RUN cargo fetch
 RUN cargo build
 RUN cargo clippy

Justfile

@@ -35,5 +35,5 @@ pr PR_NUMBER CMD:
     docker run -i --rm -e GITHUB_TOKEN=$(gh auth token) git-ai-pr-tester bash -c "{{CMD}}"
 
 # Sync a specific PR with origin/main
-sync-pr PR_NUM:
-    just pr {{PR_NUM}} "git merge origin/main --no-edit && cargo fmt --check && cargo check && git push origin"
+sync-pr PR_NUM CMD = "date":
+    just pr {{PR_NUM}} "git merge origin/main --no-edit && {{CMD}} && cargo fmt --check && cargo check && git push origin"