#663 Fix local imports and OpenAI-compatible cache

Summary

• Restore local path handling in advanced onboarding imports so /etc/nix-darwin, ~/..., path:..., and relative paths select an existing config directory instead of being treated as repository refs.
• Reject path-like values in the Rust repo import parser to protect direct IPC callers from cloning guessed GitHub repos.
• Replace stale vllm OpenAI-compatible cache/subscription keys with openai_compatible / openaiCompatibleApiBaseUrl.

Test Plan

• bun run test:unit -- src/components/widget/onboarding/lib/flake-ref.test.ts src/components/widget/settings/settings-dialog.test.tsx src/components/widget/settings/ai-models-tab.test.tsx
• cargo +stable test --manifest-path src-tauri/Cargo.toml bootstrap::import::tests -- --nocapture (from apps/native; passes with one pre-existing float fallback warning)

Docs

• No docs update needed