#22425: chore: make prepare git hooks setup cross-platform

## Summary - Problem: The existing prepare script uses POSIX shell syntax which produces confusing output on Windows during pnpm install. - Why it matters: Windows contributors see misleading "The system cannot find the path specified." messages even though installation succeeds. - What changed: Replaced the shell-based prepare command with a small Node script (scripts/setup-git-hooks.mjs) that performs the same checks in a cross-platform way. - What did NOT change (scope boundary): Behavior and scope remain identical — core.hooksPath is only set when git is available, inside a work tree, and git-hooks/ exists. The install process remains non-fatal. ## Change Type (select all) - [ ] Bug fix - [ ] Feature - [ ] Refactor - [ ] Docs - [ ] Security hardening - [x] Chore/infra ## Scope (select all touched areas) - [ ] Gateway / orchestration - [ ] Skills / tool execution - [ ] Auth / tokens - [ ] Memory / storage - [ ] Integrations - [ ] API / contracts - [ ] UI / DX - [x] CI/CD / infra ## Linked Issue/PR - Closes # - Related # None — improvement discovered during Windows setup. ## User-visible / Behavior Changes None. ## Security Impact (required) - New permissions/capabilities? (No) - Secrets/tokens handling changed? (No) - New/changed network calls? (No) - Command/tool execution surface changed? (No) - Data access scope changed? (No) - If any `Yes`, explain risk + mitigation: None. ## Repro + Verification ### Environment - OS: Windows 11 - Runtime/container: Node v24.13.0, pnpm v10.23.0 - Model/provider: N/A - Integration/channel (if any): N/A - Relevant config (redacted): Default repo configuration ### Steps 1. Run pnpm install on Windows before this change. 2. Observe misleading shell-related error message. 3. Apply this PR and run pnpm install again. ### Expected Clean install output with no POSIX shell error messages. ### Actual Install succeeds without confusing Windows-specific shell error output. ## Evidence - [x] Failing test/log before + passing after ## Human Verification (required) - Verified scenarios: Fresh install on Windows inside a git work tree. - Edge cases checked: Non-git directory; git not available; git-hooks directory missing. - What you did **not** verify: macOS/Linux environments (behavior unchanged by design). ## Compatibility / Migration - Backward compatible? (Yes) - Config/env changes? (No) - Migration needed? (No) - If yes, exact upgrade steps: None. ## Failure Recovery (if this breaks) - How to disable/revert this change quickly: Revert this PR commit. - Files/config to restore: Restore previous prepare script in package.json. - Known bad symptoms reviewers should watch for: git hooks not being configured automatically. ## Risks and Mitigations None. <!-- greptile_comment --> <h3>Greptile Summary</h3> Replaced POSIX shell-based git hooks setup with a cross-platform Node.js script (`scripts/setup-git-hooks.mjs`) to eliminate confusing error messages on Windows during `pnpm install`. The changes successfully achieve the stated goal of cross-platform compatibility. The new script properly checks for git availability, work tree status, and sets `core.hooksPath` with appropriate error handling. **Key observations:** - The new script adds a check for `git-hooks/` directory existence (lines 27-30) that the original shell command did not have - This is actually an improvement (avoids setting hooks path to non-existent directory in npm package installations), but represents a minor behavior change beyond just "cross-platform translation" - The PR description states "Behavior and scope remain identical" but this added check is technically a scope enhancement, albeit a sensible one - All error paths correctly exit with code 0 to maintain non-fatal install behavior - The implementation is clean, well-structured, and follows Node.js best practices <h3>Confidence Score: 5/5</h3> - This PR is safe to merge with minimal risk - The changes are well-contained to the prepare script, properly handle all edge cases, maintain backward compatibility, and improve cross-platform support. The added directory existence check is a minor enhancement that makes the behavior cleaner without breaking existing functionality. - No files require special attention _{Last reviewed commit: baa711b} <!-- greptile_other_comments_section --> _{(2/5) Greptile learns from your feedback when you react with thumbs up/down!} <!-- /greptile_comment -->