Support the `@private` JSDoc directive to exclude private APIs from emitted type declarations

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### 🔍 Search Terms

"private jsdoc"

### ✅ Viability Checklist

- [x] This wouldn't be a breaking change in existing TypeScript/JavaScript code
- [x] This wouldn't change the runtime behavior of existing JavaScript code
- [x] This could be implemented without emitting different JS based on the types of the expressions
- [x] This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, new syntax sugar for JS, etc.)
- [x] This isn't a request to add a new utility type: https://github.com/microsoft/TypeScript/wiki/No-New-Utility-Types
- [x] This feature would agree with the rest of our Design Goals: https://github.com/Microsoft/TypeScript/wiki/TypeScript-Design-Goals

### ⭐ Suggestion

Could properties, functions, and classes annotated with the [`@private`](https://jsdoc.app/tags-private) JSDoc directive be omitted from the emitted declarations?

tsc should throw an error if a symbol is marked as `@private`, but is actually imported/exported from another declaration file or used in the signature of another symbol like a function parameter or return type. (And therefore isn't actually an internal API.)

I'm wary this may break some projects if implemented without an opt-in, so it may require an option to enable this behavior, to preserve backward compatibility.

#### Source

> The `@private` tag marks a symbol as private, or not meant for general use. Private members are not shown in the generated output…
> …
> The `@private` tag is equivalent to `@access private`.
>
> — https://jsdoc.app/tags-private

Based on this, it may be worth also doing it for [`@access private`](https://jsdoc.app/tags-access) as well.

> Private members are not shown in the generated output…
>
> — https://jsdoc.app/tags-access

### 📃 Motivating Example

I maintain a [svgo](https://github.com/svg/svgo), a library that is written in JavaScript and typed with JSDoc directives, and uses tsc to emit declaration files.

As a library normally has an intended public API, afaik there's no need to distribute type declarations for the internal API.

### 💻 Use Cases

This is just to reduce the amount of type declarations served to developers if they aren't needed, reducing the size of the package on npm a little.

No workaround is currently needed, assuming the project is a module that uses `exports` rather than `main`, as we can limit the public API ourselves. The extra types do not cause any harm, it just makes the final package a little bigger.

For projects that use `main` instead of `exports` in their `package.json`, this may leak more private APIs that end-users may accidently consume and believe to be part of the public interface.

Bắt đầu bằng cách tái hiện trường hợp JavaScript/JSDoc làm cơ sở từ svgo với việc phát sinh khai báo TypeScript. Xác định @private và có thể cả @access private ảnh hưởng như thế nào đến các khai báo được phát sinh, bao gồm các lỗi đối với những symbol được export hoặc được tham chiếu trong signature, đồng thời xác định liệu có cần một tùy chọn opt-in để đảm bảo khả năng tương thích hay không.

Do mô hình lập chỉ mục viết ra từ nội dung của issue.