Use real home directory for global installer paths

[aiirvizionz]

Summary

• use USERPROFILE / os.homedir() instead of the literal ~ for global adapter install paths when HOME is unset
• add a regression test for bun/aube global node_modules path resolution

Why

Node does not expand ~ in paths. In Windows or HOME-less CI/container environments, the previous fallback caused sh1pt to check a literal ~/.bun or ~/.aube directory and miss already-installed global adapter packages.

Validation

• corepack pnpm install --frozen-lockfile
• corepack pnpm --filter @profullstack/sh1pt-core --filter @profullstack/sh1pt-policy --filter @profullstack/sh1pt-action-packs --filter @profullstack/sh1pt-actions-fleet-core --filter @profullstack/sh1pt-openapi build
• corepack pnpm exec vitest run packages/cli/src/installer.test.ts
• corepack pnpm --filter @profullstack/sh1pt typecheck
• git diff --check