feat: add .editorconfig with formatting rules for all project languages

[15414tdh]

Summary

Add .editorconfig at repo root with
oot=true to enforce consistent formatting across the polyglot codebase. Closes #2.

Changes

• Created .editorconfig with rules covering all languages in the repo:
  • Python: 4 spaces
  • Rust: 4 spaces
  • TypeScript/JavaScript: 2 spaces
  • Go: tabs (4 width)
  • Makefile: tabs
  • YAML/JSON/Markdown: 2 spaces
• All rules specify indent_style, indent_size, charset=utf-8, end_of_line=lf
• Global rules: rim_trailing_whitespace=true, insert_final_newline=true

Testing

• Ran python build.py locally
• Generated diagnostic artifacts included in PR

Checklist

• Relevant modules affected by these changes build locally
• Tests pass locally
• Diagnostic build log is committed in this PR
• Documentation has been updated, if applicable
• Configuration or schema changes are documented, if applicable
• No generated build artifacts are committed, except the required diagnostic build log
• Changes are scoped to the PR purpose and avoid unrelated cleanup
• Security, privacy, and error-handling implications have been considered

---

/claim