Add minimal user-defined functions implementation

[rkalis]

• Add top-level user-defined function syntax
  • Functions can return a single value or nothing
• Add import syntax
• Imports are resolved and flattened into a single AST before compiler traversals
• Used functions are defined at the top of a contract, their function
  bodies are compiled with a separate GenerateTargetTraversal + optimisations
• Update builtin function compilation to self-document their bytecode
• Update docs & release notes

This version does NOT YET support:

• Multiple return values / tuples
• Proper SDK debugging integration
• Nested / multiple returns in a function
• Advanced optimisations
• Global constants
• Cross-file pragma resolutions

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated (UTC)
cashscript	Ready	Preview, Comment	Jun 26, 2026 2:05pm

[codecov]

Codecov Report

❌ Patch coverage is 96.04520% with 14 lines in your changes missing coverage. Please review.
✅ Project coverage is 86.31%. Comparing base (53f286b) to head (7edbfc4).

Files with missing lines	Patch %	Lines
packages/cashc/src/Errors.ts	85.00%	3 Missing ⚠️
...kages/cashc/src/print/OutputSourceCodeTraversal.ts	82.35%	3 Missing ⚠️
packages/cashc/src/ast/AST.ts	91.30%	2 Missing ⚠️
.../cashc/src/semantic/EnsureFinalRequireTraversal.ts	92.85%	2 Missing ⚠️
packages/cashc/src/ast/AstBuilder.ts	97.14%	1 Missing ⚠️
packages/cashc/src/ast/AstTraversal.ts	90.00%	1 Missing ⚠️
...es/cashc/src/generation/GenerateTargetTraversal.ts	96.87%	1 Missing ⚠️
packages/utils/src/types.ts	66.66%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@ Coverage Diff @@## next #413 +/- ##
==========================================
+ Coverage 85.69% 86.31% +0.61% 
==========================================
Files 51 55 +4 Lines 4041 4318 +277 Branches 757 805 +48 ==========================================
+ Hits 3463 3727 +264 - Misses 453 465 +12 - Partials 125 126 +1 

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.