Include depth info in SelectionSetTooDeep error

Change ValidationError::SelectionSetTooDeep from a single Pos variant to a struct containing depth, max_depth, and pos. Update OperationValidator to return the new struct, adjust pattern matches to destructure the new variant, and update validation snapshots and an integration test to expect the more informative error message (includes actual and allowed depths).

Author: scoop1120

crates/core-subsystem/core-resolver/src/validation/operation_validator.rs

@@ -74,7 +74,11 @@ impl<'a> OperationValidator<'a> {
                     self.normal_query_depth_limit
                 };
                 if depth > max_depth {
-                    Err(ValidationError::SelectionSetTooDeep(pos))
+                    Err(ValidationError::SelectionSetTooDeep {
+                        depth,
+                        max_depth,
+                        pos,
+                    })
                 } else {
                     Ok(true)
                 }

crates/core-subsystem/core-resolver/src/validation/snapshots/introspection_query_depth_limit_direct-2.snap

@@ -3,7 +3,9 @@ source: crates/core-subsystem/core-resolver/src/validation/document_validator.rs
 expression: validator.validate(create_query_document(query))
 ---
 Err(
-    SelectionSetTooDeep(
-        Pos(5:25),
-    ),
+    SelectionSetTooDeep {
+        depth: 3,
+        max_depth: 2,
+        pos: Pos(5:25),
+    },
 )

crates/core-subsystem/core-resolver/src/validation/snapshots/query_depth_limit_direct-2.snap

@@ -3,7 +3,9 @@ source: crates/core-subsystem/core-resolver/src/validation/document_validator.rs
 expression: validator.validate(create_query_document(query))
 ---
 Err(
-    SelectionSetTooDeep(
-        Pos(8:37),
-    ),
+    SelectionSetTooDeep {
+        depth: 6,
+        max_depth: 5,
+        pos: Pos(8:37),
+    },
 )

crates/core-subsystem/core-resolver/src/validation/snapshots/query_depth_limit_through_fragment-2.snap

@@ -3,7 +3,9 @@ source: crates/core-subsystem/core-resolver/src/validation/document_validator.rs
 expression: validator.validate(create_query_document(query))
 ---
 Err(
-    SelectionSetTooDeep(
-        Pos(14:25),
-    ),
+    SelectionSetTooDeep {
+        depth: 6,
+        max_depth: 5,
+        pos: Pos(14:25),
+    },
 )

crates/core-subsystem/core-resolver/src/validation/validation_error.rs

@@ -72,8 +72,12 @@ pub enum ValidationError {
     #[error("Fragment cycle detected: {0}")]
     FragmentCycle(String, Pos),
 
-    #[error("Selection set too deep")]
-    SelectionSetTooDeep(Pos),
+    #[error("Selection set depth {depth} exceeds the maximum allowed depth {max_depth}")]
+    SelectionSetTooDeep {
+        depth: usize,
+        max_depth: usize,
+        pos: Pos,
+    },
 
     #[error("Invalid value for '{value_name}': {range_detail}, {value_detail}")]
     ValueOutOfRange {
@@ -106,7 +110,7 @@ impl ValidationError {
             ValidationError::MultipleOperationsUnmatchedOperationName(_) => vec![],
             ValidationError::InvalidArgumentType { pos, .. } => vec![*pos],
             ValidationError::FragmentCycle(_, pos) => vec![*pos],
-            ValidationError::SelectionSetTooDeep(pos) => vec![*pos],
+            ValidationError::SelectionSetTooDeep { pos, .. } => vec![*pos],
             ValidationError::ValueOutOfRange { pos, .. } => vec![*pos],
         }
     }

integration-tests/error-reporting/tests/over-the-limit-query-depth.exotest

@@ -23,7 +23,7 @@ response: |
     {
       "errors": [
         {
-          "message": "Selection set too deep",
+          "message": "Selection set depth 6 exceeds the maximum allowed depth 5",
           "locations": [
             {
               "line": 11,