v1.4.0

Cross-repo linking: connect related repos, generate RELATED_REPOS.md in both, and re-sync when the authoritative repo changes.

Added

• /hacky-hours link — new command for connecting two related repos. Run in the dependent repo, pointing at the authoritative repo's local path. Reads both repos' design docs, infers the relationship and source-of-truth boundary, asks clarifying questions, and generates RELATED_REPOS.md in both repos plus a ## Related Repositories section in this repo's CLAUDE.md. --sync flag re-reads the authoritative repo's current design docs and surfaces what's changed since the link was established — without auto-updating anything.
• RELATED_REPOS.md template (02-design/RELATED_REPOS.md) — new Level 2 design artifact for documenting cross-repo relationships. Contains: relationship table (role + source-of-truth boundary per repo), Decision Routing Table (design question → doc in other repo), and cross-repo coordination protocol. Single file with one ## Repo: section per related repo.

Changed

• Level 2 guidance — added RELATED_REPOS.md to the "which docs does your project need?" table, prompted when ARCHITECTURE.md indicates a multi-repo split. Also added link suggestion to the Claude Guidance section of 02-design/README.md.
• Help message — added --- Multi-repo --- section with link entry.
• Subcommand help — added help link entry documenting both initial link and --sync usage.