fix(ts-parser): normalize monorepo package paths

[dajiaohuang]

What type of PR is this?

fix

Check the PR title.

• This PR title matches the format: <type>(optional scope): <description>
• The description is user-oriented and clear enough to understand.
• No user-documentation update is required; this makes the implementation match the documented cross-platform path format.

(Optional) Translate the PR title into Chinese.

fix(ts-parser): 统一 monorepo 包路径分隔符

(Optional) More detailed description for this PR(en: English/zh: Chinese).

en:

MonorepoUtils previously copied path.relative() directly into MonorepoPackage.path. On Windows that produces backslashes, so the existing Eden and pnpm monorepo tests received packages\core instead of the portable packages/core value used by the TypeScript UniAST mapping.

This change normalizes only the relative package identity to forward slashes, matching the parser's existing path utilities. absolutePath remains unchanged for host-native filesystem access, so filesystem behavior and public interfaces are preserved.

The existing focused tests already cover the expected portable value and reproduced the defect on Windows.

Validation on Windows:

• npx jest src/utils/test/monorepo.test.ts --runInBand --no-cache — 8/8 passed after the fix (2 failures before it)
• npm run build — passed
• npm run typecheck — passed
• npx eslint src/utils/monorepo.ts — passed
• npm test -- --runInBand — 9/10 suites and 174/175 tests passed; the sole remaining failure is the pre-existing integration expectation that counts two packages although merged PR fix: no record packagejson in project root path #160 intentionally added the root package, and is unrelated to path separators

Tradeoff: serialized package identities are now platform-independent while absolute paths intentionally retain native separators.

zh(optional):

将 monorepo 的相对包标识统一为正斜杠，同时保留用于文件系统访问的原生绝对路径。

(Optional) Which issue(s) this PR fixes:

Fixes #202

(optional) The PR that updates user documentation:

N/A