Prepare Branch Context

Build a standardized, actionable context pack for the current branch so follow-up agents can act immediately without re-discovery.

Execution Mode: This skill MUST always be executed in a subagent. Default subagent type is thrifty. Use a different subagent type only when explicitly requested.

Preferred invocation:

• prepare-branch-context from <base-branch>

Optional extensions:

• prepare-branch-context (auto-resolve base branch)
• prepare-branch-context from <base-branch> commits <rev-range>
• prepare-branch-context from <base-branch> files <path1,path2,...>

Default behavior:

• If <base-branch> is omitted, auto-detect the repo default branch first. If that fails, fall back to staging and say so.