fixed a few minor inconsistencies

Author: rxdu

include/graph/graph.hpp

@@ -70,7 +70,7 @@ namespace xmotion {
  * **Vertex Operations (Strong Guarantee)**
  * - AddVertex(): Strong guarantee - vertex fully added or graph unchanged
  * - RemoveVertex(): Strong guarantee - vertex fully removed or graph unchanged  
- * - FindVertex(): No-throw for valid inputs, throws std::out_of_range for invalid IDs
+ * - FindVertex(): No-throw for valid inputs, throws ElementNotFoundError for invalid IDs
  * 
  * **Edge Operations (Strong Guarantee)**
  * - AddEdge(): Strong guarantee - edge fully added or graph unchanged
@@ -100,8 +100,8 @@ namespace xmotion {
  * @section error_conditions Error Conditions and Exceptions
  * 
  * **std::bad_alloc**: Memory allocation failures (from std::unordered_map or std::unique_ptr)
- * **std::invalid_argument**: Invalid input parameters (e.g., in tree operations)
- * **std::logic_error**: Violation of class invariants (e.g., tree structure violations)
+ * **InvalidArgumentError**: Invalid input parameters (e.g., in tree operations)
+ * **StructureViolationError**: Violation of class invariants (e.g., tree structure violations)
  * **State copy constructor exceptions**: Propagated with strong guarantee via RAII
  * 
  * @section thread_safety_exceptions Thread Safety and Exceptions

include/graph/impl/default_indexer.hpp

@@ -27,8 +27,8 @@
  *
  */
 
-#ifndef STATE_INDEXER_HPP
-#define STATE_INDEXER_HPP
+#ifndef DEFAULT_INDEXER_HPP
+#define DEFAULT_INDEXER_HPP
 
 #include <type_traits>
 #include <memory>

include/graph/impl/graph_impl.hpp

@@ -241,7 +241,7 @@ Graph<State, Transition, StateIndexer>::ObtainVertexFromVertexMap(State state) {
   if (it == vertex_map_.end()) {
     // Exception-safe vertex creation using unique_ptr with move semantics
     std::unique_ptr<Vertex> new_vertex(new Vertex(std::move(state), state_id));
-    new_vertex->search_parent = vertex_end();
+    // Note: search_parent initialization removed - field is deprecated
     auto result = vertex_map_.insert(std::make_pair(state_id, std::move(new_vertex)));
     return vertex_iterator(result.first);
   }

include/graph/tree.hpp

@@ -64,8 +64,8 @@ namespace xmotion {
  * - AddRoot(): Strong guarantee - root added or tree unchanged
  * - AddEdge(): Strong guarantee - maintains tree structure invariants
  * - RemoveSubtree(): Strong guarantee - subtree fully removed or unchanged
- * - GetParentVertex(): Throws std::invalid_argument if vertex not found,
- *                       std::logic_error if tree invariant violated
+ * - GetParentVertex(): Throws ElementNotFoundError if vertex not found,
+ *                       StructureViolationError if tree invariant violated
  * 
  * **Tree Query Operations (No-throw Guarantee)**
  * - GetRootVertex(): No-throw - returns end() if no root