fix: preserve TTY in dev mode by inlining tsx invocation

The `cli` and `dev` scripts used `pnpm tsx src/bin.ts`, which is
shorthand for `pnpm run tsx` — a nested pnpm lifecycle spawn. The inner
spawn loses TTY inheritance, so `process.stdin.isTTY` is undefined and
interactive commands like `sentry init` fall back to non-interactive mode.

Replace `pnpm tsx` with the inlined `tsx --import ./script/require-shim.mjs`
in `cli` and `dev` only. This keeps a single pnpm lifecycle layer that uses
`stdio: 'inherit'`, preserving the terminal's TTY. The `tsx` script alias
remains for the 19+ non-interactive scripts (build, generate, check, bench).

Author: BYK