fix: node resolution paths starting with src/ don't work

[sod]

These TypeScript alias paths are not converted by tsc to relative imports. Either use a postprocessor like tsc-alias that converts those aliased path, or don't use them to begin with.

I opted in this PR with the option that doesn't add a dependency.

Fixes #62

[macroscopeapp]

Replace src/-prefixed absolute imports with relative parent-based imports in packages/node to fix broken Node resolution

Update exposure-related modules to use relative imports instead of src/-prefixed absolute paths, including cache and hash utilities and ExperimentUser type references.

📍Where to Start

Start with packages/node exposure module imports in packages/node/src/exposure/exposure.ts to see the pattern applied across files.

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Macroscope summarized 92e424f.

[zhukaihan]

Merging. Test errors are expected as they don't have access to tokens. Running them on main.