build(deps): promote TypeScript 7 RC to stable 7.0.2

[lukecotter]

What

Promotes the native TypeScript 7 compiler from the RC (7.0.1-rc) to the stable GA release (typescript@7.0.2), now that TypeScript 7.0 has shipped GA.

• package.json: typescript-7 alias npm:typescript@rc → npm:typescript@^7.0.2 (tsc used by pnpm typecheck).
• pnpm-lock.yaml: resolves typescript-7 → typescript@7.0.2.
• AGENTS.md: note explaining why the dual-compiler setup stays.

Why the dual-compiler setup is unchanged

typescript-eslint@8.63.0 still declares peer typescript >=4.8.4 <6.1.0 and depends on the TS programmatic API, which TS 7.0 does not ship (arrives in TS 7.1). So the package resolved under the name typescript must remain the @typescript/typescript6@6.0.2 bridge (also used by typescript-eslint and Docusaurus). This PR only bumps the typescript-7 alias.

Verification

• tsc --version → 7.0.2
• pnpm typecheck (TS7, -b --force) → pass
• pnpm typecheck:tsc6 (6.0 parity) → pass
• pnpm lint → 0 errors
• pnpm build → pass
• pnpm test → 962/962 pass