feat(hoist): pre-compute loop hoisting metadata at compilation time (#483)

Introduce a compiler pass that analyzes and pre-computes loop hoisting information
during policy compilation. This hoisted metadata is stored in lookup tables and made
available to downstream consumers:

- interpreter: use HoistedLoop entries during evaluation (replaces runtime scanning)
- type inference: can leverage pre-computed loop structure for type propagation
- RVM compiler: will consume hoisting metadata for optimized bytecode generation

Changes:
- populate loop hoisting tables during engine preparation and query snippet execution
- refactor eval_stmts_in_loop and eval_output_expr_in_loop to consume HoistedLoop directly
- add helper methods for accessing loop expressions, collections, and indices from HoistedLoop
- extend Lookup with get_checked and into_slots for safe query context access and merging

Signed-off-by: Anand Krishnamoorthi <anakrish@microsoft.com>

src/schema/tests/validate/resource.rs

@@ -857,7 +857,7 @@ fn test_complex_nested_azure_template_validation() {
 
     let value = Value::from(valid_template);
     let result = SchemaValidator::validate(&value, &schema);
-    std::dbg!(&result);
+
     assert!(
         result.is_ok(),
         "Complex valid template should pass validation"