Start Linked Worktree

Resolve one mode before changing the worktree, execute only that mode, and return its verified service URLs.

Establish Context

1. Resolve the repository root with git rev-parse --show-toplevel.
2. Read the repository AGENTS.md, when present, and read worktrees/worktree-modes.yaml completely, including its comments. Treat the YAML as the source of truth for available modes, selection guidance, scaffolding, startup, readiness, printable values, and logs. Read any file it explicitly references before acting.
3. Confirm .git is a file. Refuse to run worktree lifecycle commands in the primary checkout.

Resolve the Mode Before Acting