chore: add .claude project scaffolding

Agent/project config carried alongside the WIP snapshot.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: hyperpolymath

.claude/PROJECT.md

@@ -0,0 +1,33 @@
+# BetLang - Claude Code Instructions
+
+This repository contains the BetLang programming language compiler and tooling.
+
+## Project Structure
+
+```
+betlang/
+├── .claude/         # AI assistant instructions
+├── .git/           # Version control
+├── .gitignore      # Git ignore rules
+├── .editorconfig   # Editor configuration
+└── ...             # Compiler files
+```
+
+## Build Commands
+
+Refer to project-specific documentation.
+
+## Coding Conventions
+
+- Follow hyperpolymath standards
+- All code must have SPDX license headers
+- Use approved languages only (see CLAUDE.md)
+- Document all non-obvious decisions
+
+## Security
+
+- No hardcoded secrets
+- All secrets through environment variables or secret management
+- SHA-pinned dependencies where applicable
+- HTTPS only, no HTTP URLs
+- No MD5/SHA1 for security purposes