axon-frontend 0.2.0

AXON compiler frontend — lexer, parser, AST, epistemic type system, type checker, IR generator, compile-time checker. Zero runtime dependencies (no tokio/axum/sqlx/reqwest); consumable by any tool that analyses AXON source without running it. v0.2.0 adds Fase 13 typed channels (channel/emit/publish/discover) + `channel_analysis` module for LSP integration.