feat!: Introduce structured destructuring plans for bindings (#485)

- add a dedicated `compiler/destructuring_planner` feature that precomputes binding plans for assignments, parameters, and `some in` expressions
- enrich `ScopeContext` with same-scope tracking, local scheduling hints, and module globals so the planner enforces := shadowing rules without blocking parent scopes
- wire the planner through compiler, hoist, interpreter, and engine paths while updating binding plan variants and adding query traversal helpers for dependency analysis
- document the new planner architecture and ship interpreter regressions that exercise nested destructuring, shadowing, and error reporting

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

src/lib.rs

@@ -35,6 +35,7 @@ mod lookup;
 mod number;
 mod parser;
 mod policy_info;
+mod query;
 #[cfg(feature = "azure_policy")]
 pub mod registry;
 mod scheduler;