feat: expose JIT compiler via CLI command

Add `lux compile <file>` command that compiles and runs Lux code using
the Cranelift JIT compiler. Includes --benchmark flag for timing.

- Add compile_file() function in main.rs
- Add jit_test.lux example with fib(30) + factorial(10)
- Update VISION.md status

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

docs/VISION.md

@@ -128,11 +128,11 @@ fn retry<F>(action: F, times: Int): Result
 
 | Feature | Effort | Why It Matters |
 |---------|--------|----------------|
-| **Module System** | 2-3 weeks | Can't build real apps without imports |
+| **Module System** | Done | Imports, exports, aliases, selective imports |
 | **Standard Library** | Done | List.map, String.split, Option.map, etc. |
 | **File/Network Effects** | 1-2 weeks | Real IO beyond Console |
 | **Better Error Messages** | 2-3 weeks | Elm-quality diagnostics |
-| **JS/WASM Compilation** | 4-6 weeks | Deploy to browsers/servers |
+| **Full Compilation** | 4-6 weeks | Cranelift JIT exists for numeric code; needs strings, ADTs, effects |
 
 ### Needed for Full Vision (Phase 3: Differentiation)
 
@@ -245,7 +245,7 @@ Hint: Maybe you need to parse the string?
 ## Immediate Next Steps
 
 1. ~~**Standard Library**~~ - Done! List, String, Option, Result operations
-2. **Module System** - `import`, `export`, namespaces
+2. ~~**Module System**~~ - Done! Imports, exports, aliases, selective imports
 3. **File Effect** - `FileSystem.read`, `FileSystem.write`
 4. **Error Message Overhaul** - Source snippets, suggestions, colors
 5. **JavaScript Backend** - Compile to runnable JS