fix: detect Windows npm CLI shims

[adamkane]

Summary

• skip npm's extensionless POSIX shim when resolving CLIs on Windows
• invoke .cmd and .bat launchers through a quoted cmd.exe command string
• keep direct execution for native binaries and add Windows regression coverage

This prevents the session-start profiler from repeatedly reporting an installed Vercel CLI as missing. It also avoids Node's deprecated shell: true plus argument-array form.

Fixes #89
Fixes #95
Fixes #105

Verification

• bun test hooks/session-start-profiler-platform.test.ts (4 passed)
• bun run typecheck
• bun run build:hooks
• live Windows hook smoke test with npm-installed Vercel CLI 56.2.0 (no missing/outdated warning)

Existing upstream baseline failures

The broader Windows suite was also attempted. Untouched upstream/main currently fails build:from-skills:check and validate for stale template includes/command catalog rules; the full suite reports the same unrelated template and Windows path failures. This PR changes only the profiler source, generated hook, and its platform regression test.

[adamkane]

@Melkeydev Could you please review this Windows CLI detection fix when you have a chance? The focused platform tests, hook build, and typecheck pass; the unrelated upstream baseline failures are documented in the PR description.