organize code properly

Maintain clear code organization by placing code in appropriate files, directories, and modules. Respect module boundaries and create logical directory structures that reflect the code’s purpose and domain.

Key principles:

• Place types in dedicated type files (e.g., move StagehandInitResult to types/evals.ts)
• Create domain-specific directories for related functionality (e.g., lib/a11y for accessibility utilities)
• Respect module boundaries (evals should reference dist, not lib)
• Group related functions in appropriately named files (prompts and prompt building functions belong in prompts.ts)

Example of proper organization:

// Before: accessibility functions mixed in handlers
// lib/handlers/observeHandler.ts
type AccessibilityNode = { ... }
function formatSimplifiedTree() { ... }

// After: dedicated accessibility module  
// lib/a11y/utils.ts
type AccessibilityNode = { ... }
function formatSimplifiedTree() { ... }

This approach improves code discoverability, reduces coupling between modules, and makes the codebase easier to navigate and maintain.