fix: add stdio cli help handling

[Viodmian]

Summary

• Add explicit --help / -h handling for the Supabase stdio CLI.
• Keep --version behavior while moving CLI metadata parsing into a small helper.
• Normalize unknown top-level options into a concise non-zero CLI error instead of printing a raw parseArgs stack trace and exiting 0.

Fixes #296.

Verification

• From packages/mcp-utils: .\node_modules\.bin\tsup.cmd --config tsup.config.ts
• With CI=1, from packages/mcp-server-supabase: .\node_modules\.bin\vitest.cmd run --project unit src/transports/stdio-cli.test.ts
• From packages/mcp-server-supabase: .\node_modules\.bin\tsc.cmd --noEmit
• From packages/mcp-server-supabase: .\node_modules\.bin\tsup.cmd --config tsup.config.ts
• From repo root: .\node_modules\.bin\biome.cmd 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
• git diff --check
• node dist\transports\stdio.js --help
• node dist\transports\stdio.js --version
• node dist\transports\stdio.js --definitely-not-real
• node dist\transports\stdio.js still requires a Supabase PAT for normal server startup.

Note: corepack pnpm install --frozen-lockfile mostly installed dependencies but exited non-zero locally because pnpm 11 blocked dependency build scripts and could not create the supabase binary. The package tests/builds above were run directly from the installed local package binaries after install.