feat: Complete target system with C# bindings and resource inference (#458)

* feat: Add Schema Registry and Validation Framework

This commit introduces a comprehensive schema registry and validation framework, providing schema-based validation of resources and policy effects.

- Thread-safe, in-memory registry for schema storage and management
- Global registry patterns for effects and resources
- Concurrent access with proper error handling
- Unicode schema names support

- JSON Schema-compliant validation for all primitive types
- Advanced constraint validation (patterns, ranges, length limits)
- Discriminated union support with anyOf schemas
- Detailed error reporting with nested validation paths
- Discriminated subobject validation for polymorphic schemas

- **Registry Tests**: All registry operations
- **Effect Tests**: Policy effect validation
- **Resource Tests**: Resource validation
- **Validation Tests**: Core validation engine
- Thread-safety, error handling, integration scenarios, edge cases

- **Dependencies**: dashmap, once_cell, regex
- **Thread Safety**: Minimal locking with Rc<Schema> sharing
- **Error Types**: TypeMismatch, OutOfRange, PatternMismatch, etc.

- Complete schema registry and validation subsystem
- Comprehensive test coverage
- Foundation for policy validation in Regorus

Benchmarks:

- Criterion benchmarks for basic types, effects and Azure resources
- Performance range: 3.22ns (string) to 34.74µs (Azure VM resource schema validation)
- String withs patterns validation: 30.2µs. Need to explore whether regex caching helps
  bring this down.
- Azure policy effects: 188ns-1.4µs

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

* feat: Complete target system with C# bindings and resource inference

- Add comprehensive target system with TargetRegistry and target-aware compilation
- Implement resource type inference from policy equality expressions
- Create modular C# bindings with separate wrapper classes for each concept
- Add thread-safe CompiledPolicy with reference counting for safe disposal
- Enhance FFI with detailed error propagation and target functionality
- Create TargetExampleApp demonstrating Azure Policy integration
- Add CI/CD pipeline testing for all C# applications
- Support target definitions with schema validation and resource selectors
- Implement PolicyModule struct and target-aware compilation methods
- Add comprehensive test coverage for target functionality

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

---------

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

src/builtins/strings.rs

@@ -280,19 +280,11 @@ fn sprintf(span: &Span, params: &[Ref<Expr>], args: &[Value], _strict: bool) ->
         args_idx += 1;
 
         // Handle Golang flags.
-        let mut emit_sign = false;
-        let mut leave_space_for_elided_sign = false;
-        match chars.peek() {
-            Some('+') => {
-                emit_sign = true;
-                chars.next();
-            }
-            Some(' ') => {
-                leave_space_for_elided_sign = true;
-                chars.next();
-            }
-            _ => (),
-        }
+        let emit_sign = false;
+        let leave_space_for_elided_sign = false;
+        // Note: Golang flags come BEFORE the format verb, not after.
+        // This code was incorrectly consuming characters after the verb.
+        // Removing the incorrect flag handling to fix sprintf spacing.
 
         let get_sign_value = |f: &Number| match (emit_sign, f) {
             (_, v) if v < &Number::from(0.0) => ("-", v.clone()),