Handle Supabase stdio CLI help flags

[Dolpme]

Summary

• add stdio CLI handling for --help/-h before the server starts
• keep --version working and add -v
• normalize unknown top-level flags to a concise non-zero CLI error instead of a parseArgs stack trace

Fixes #296.

Verification

• CI=true pnpm exec vitest --run src/transports/stdio-cli.test.ts --project unit from packages/mcp-server-supabase
• CI=true pnpm --filter @supabase/mcp-server-supabase typecheck
• pnpm exec biome check packages/mcp-server-supabase/src/transports/stdio.ts packages/mcp-server-supabase/src/transports/stdio-cli.ts packages/mcp-server-supabase/src/transports/stdio-cli.test.ts
• pnpm --filter @supabase/mcp-server-supabase build
• node packages/mcp-server-supabase/dist/transports/stdio.js --help
• node packages/mcp-server-supabase/dist/transports/stdio.js -h
• node packages/mcp-server-supabase/dist/transports/stdio.js --version
• node packages/mcp-server-supabase/dist/transports/stdio.js -v
• node packages/mcp-server-supabase/dist/transports/stdio.js --definitely-not-a-real-flag exits 1 with concise error
• git diff --check