vp pack --dts crashes with TypeScript 7 due to unavailable legacy Compiler API

[labbomb]

Describe the bug

vp pack --dts crashes when the project uses typescript@7.0.2.

The declaration-generation code reads ts.sys.useCaseSensitiveFileNames, but the typescript package in TypeScript 7 does not expose the legacy Compiler API from its package root, so ts.sys is undefined.

@voidzero-dev/vite-plus-core@0.2.4 also currently declares the peer range typescript: "^5.0.0 || ^6.0.0".

Reproduction

Minimal files:

package.json

{
  "name": "vite-plus-ts7-repro",
  "private": true,
  "type": "module"
}

tsconfig.json

{
  "compilerOptions": {
    "target": "esnext",
    "module": "esnext",
    "moduleResolution": "bundler",
    "strict": true,
    "declaration": true
  },
  "include": ["src/**/*.ts"]
}

src/index.ts

export const answer = 42

Run:

pnpm --package vite-plus@0.2.4 \
  --package typescript@7.0.2 \
  --package esbuild@0.28.1 \
  dlx vp pack src/index.ts --dts

Steps to reproduce

1. Create the three files above.
2. Run the provided command.
3. Observe that the JavaScript build begins, but declaration generation crashes.

Expected behavior

Vite+ should support declaration generation with TypeScript 7, or report a clear compatibility error instead of crashing while accessing the legacy Compiler API.

Actual behavior

WARN Issues with peer dependencies found
└─┬ vite-plus 0.2.4
  └─┬ @voidzero-dev/vite-plus-core 0.2.4
    └── ✕ unmet peer typescript@"^5.0.0 || ^6.0.0": found 7.0.2

[plugin rolldown-plugin-dts:generate]
TypeError: Cannot read properties of undefined (reading 'useCaseSensitiveFileNames')
    at @voidzero-dev/vite-plus-core/dist/tsdown/tsc-CdZE7QwS.js:60:31

The failing bundled code reads:

ts.sys.useCaseSensitiveFileNames

System Info

• vite-plus: 0.2.4
• TypeScript: 7.0.2
• esbuild: 0.28.1
• Node.js: 24.6.0
• pnpm: 11.13.1
• OS: macOS arm64

Additional context

TypeScript 7 type checking itself works in the project. The incompatibility is specifically triggered by Vite+'s declaration-generation path (vp pack --dts).

Validations

• Read the Contributing Guidelines.
• Checked that there isn't already an issue for the same bug.
• Confirmed the failure occurs in a standalone Vite+ reproduction.
• Reduced the reproduction to one TypeScript source file.

[jong-kyung]

This will be resolved once #2180 is merged