Content-Addressed Functions (Unison-style hashing) #417

Overview

Implement content-addressed function storage for TRI-LANG, inspired by Unison language.

Requirements

• SHA256 hashing of normalized function ASTs
• Alpha-equivalence (variable names don't affect hash)
• Registry mapping hashes to function locations
• Support for deduplication, caching, incremental compilation

Implementation

• src/tri-lang/content_hash.zig - Hash generation (~100 LOC)
• src/tri-lang/content_registry.zig - Hash-to-location registry (~120 LOC)
• Integration into src/tri-lang/pipeline.zig (~80 LOC additions)

Status

✅ Implementation complete
✅ All tests passing (8/8 content_hash tests)
✅ Zig 0.15 compatibility fixed