Phase 4: Macro expansion in compiler

- resolve-macro: resolve symbols to macro vars via ctx
- Macro expansion in analyze-form: detects macro heads, expands, re-analyzes
- compile-ast: emits Janet data structures with resolved core fn values
- compile-and-eval uses compile-ast (no source parse roundtrip)
- eval-string routes macros through compiler (expanded at analyze time)
- Fix - mapping: core-sub (core-- doesn't exist)
- All 317 tests pass + 6 new Phase 4 macro tests

.dirge/skills/jolt-dev/SKILL.md

@@ -37,9 +37,16 @@ For evaluating Janet source strings, use the parser pipeline:
 
 When you need to mutate a local with `set`, use `(var x nil)` not `(def x nil)`. `def` creates constants.
 
+## Compiler (see also `jolt-compiler` skill)
+
+`src/jolt/compiler.janet` — Clojure→Janet source compiler with macro expansion.
+`test/compiler-test.janet` — 11 test groups covering all ops.
+
+Key design decision: **compile-and-eval emits Janet DATA STRUCTURES, not source strings**, because Janet's `eval` doesn't see `use`-imported symbols. `core-fn-values` table resolves Janet names to actual function values at compile time.
+
 ## Special Form Checklist
 
-To add a new special form to the evaluator:
+To add a new special form to the evaluator AND compiler:
 
 1. Add the name to `special-symbol?` in `src/jolt/evaluator.janet`
 2. Add a match arm in `eval-list` (the match on `name`)