Add sideEffects field to package.json to enable bundler tree-shaking

[NoopDog]

Parent: #885

Summary

package.json does not declare a sideEffects field. Without it, webpack/Turbopack conservatively assume every module in findable-ui may have side effects on import and cannot eliminate unused exports. Declaring \"sideEffects\": false (or an allowlist) tells the bundler it is safe to drop any imported module whose exports aren't actually used, which can substantially shrink consumer bundles.

Why this is zero-consumer-impact

sideEffects only changes how bundlers behave when compiling a consumer. The package's runtime behavior is unchanged. Consumers don't update any imports.

Research to do

1. Confirm the lib is side-effect free. Grep the source for anything that runs at module-evaluation time beyond declaring/exporting:
   • CSS/SCSS imports (.css, .scss, global style imports) — a quick scan found none.
   • Polyfills imported for side effects.
   • window.X = ... or similar top-level mutations.
   • console.log / logger setup at module scope.
   • Self-registering modules (e.g., pushing onto a global registry on import).
   • Event listener attachments at module scope.
2. Audit .styles.ts(x) — these should be pure emotion styled(...) definitions. Verify no module-scope side effects.
3. Audit providers / reducers — module-scope createContext(...) is fine (pure). Confirm nothing dispatches or subscribes at import.
4. Audit src/common/analytics — confirm the GA wiring is function-scoped, not side-effectful at import.
5. Test consumer bundle — in a test consumer app (e.g. data-browser), capture a bundle-analyzer report before and after the change to confirm expected shrinkage and no regressions.
6. Storybook smoke test — run storybook and confirm components still render.

Implementation options

Option A — full false:

\"sideEffects\": false

Preferred if the audit above finds no side effects. Maximum tree-shaking.

Option B — allowlist:

\"sideEffects\": [\"**/*.css\", \"**/*.scss\"]

Use if we discover specific files with required side effects. Those files are preserved even if only their side effect is imported; everything else can be dropped.

Default recommendation: Option A, unless audit surfaces counterexamples.

Testing

• npm test, npm run lint, npm run test-compile pass.
• Storybook renders all components.
• In a consumer app: bundle analyzer before/after, look for dropped chunks. No visual regressions on key pages.

Acceptance criteria

• Audit completed; any offending modules either refactored or added to the allowlist
• sideEffects field added to package.json
• Lint, tests, and tsc --noEmit pass
• Storybook renders cleanly
• Before/after bundle-analyzer screenshots from one consumer posted in PR