docs: add solution contract spec and update to polymorphic architecture

BREAKING CHANGE: Remove deprecated wrapper template and --wrapper option

- Create docs/solution_contract.md as canonical specification for:
  - Solution file structure (SOLUTIONS + get_solver() pattern)
  - SOLUTIONS metadata schema (required: class, method)
  - Judge/validation contract (JUDGE_FUNC, COMPARE_MODE priority)
  - Static/dynamic tests and generator requirements
  - Metadata layers and consistency checklist

- Update templates to polymorphic architecture:
  - template_solution.py: Add SOLUTIONS dict + get_solver()
  - template_solution_multi.py: Use multiple classes, same method name
  - Delete template_solution_wrapper.py (deprecated)

- Update scripts:
  - new_problem.bat/sh: Remove --wrapper option
  - run_tests.bat: Fix argument passing (use %* for all args)

- Update documentation:
  - README.md: Replace wrapper example with polymorphic pattern
  - README_zh-TW.md: Same updates in Chinese
  - ARCHITECTURE_MIGRATION.md: Mark Phase 4 complete

- Clean up temporary files:
  - Delete test_debug.py
  - Delete test_output.py

Author: lufftw

README.md

@@ -543,41 +543,53 @@ if __name__ == "__main__":
 
 ### 🚀 Multi-Solution Benchmarking
 
-Compare multiple approaches for the same problem:
+Compare multiple approaches for the same problem using the **polymorphic pattern**:
 
 ```python
 # solutions/0023_merge_k_sorted_lists.py
+from _runner import get_solver
 
 SOLUTIONS = {
     "default": {
-        "method": "mergeKLists_heap",
+        "class": "SolutionHeap",
+        "method": "mergeKLists",
         "complexity": "O(N log k)",
         "description": "Min Heap approach"
     },
     "divide": {
-        "method": "mergeKLists_divide",
+        "class": "SolutionDivideConquer",
+        "method": "mergeKLists",
         "complexity": "O(N log k)",
         "description": "Divide and Conquer"
     },
     "greedy": {
-        "method": "mergeKLists_greedy",
+        "class": "SolutionGreedy",
+        "method": "mergeKLists",
         "complexity": "O(kN)",
         "description": "Greedy comparison"
     },
 }
 
-class Solution:
-    def mergeKLists_heap(self, lists):
+class SolutionHeap:
+    def mergeKLists(self, lists):
         # Heap implementation
         pass
-    
-    def mergeKLists_divide(self, lists):
+
+class SolutionDivideConquer:
+    def mergeKLists(self, lists):
         # Divide & Conquer implementation
         pass
-    
-    def mergeKLists_greedy(self, lists):
+
+class SolutionGreedy:
+    def mergeKLists(self, lists):
         # Greedy implementation
         pass
+
+def solve():
+    # ... parse input ...
+    solver = get_solver(SOLUTIONS)
+    result = solver.mergeKLists(lists)
+    print(result)
 ```
 
 **Run commands:**
@@ -604,36 +616,7 @@ greedy                  44.82ms   O(kN)           3/3
 ============================================================
 ```
 
-<details>
-<summary><strong>Advanced: Wrapper Pattern for Multiple Classes</strong></summary>
-
-When you need separate classes with the same method name:
-
-```python
-class SolutionRecursive:
-    def reverseKGroup(self, head, k):
-        pass  # Recursive implementation
-
-class SolutionIterative:
-    def reverseKGroup(self, head, k):
-        pass  # Iterative implementation
-
-# Wrapper functions
-def solve_recursive(head, k):
-    return SolutionRecursive().reverseKGroup(head, k)
-
-def solve_iterative(head, k):
-    return SolutionIterative().reverseKGroup(head, k)
-
-SOLUTIONS = {
-    "default": {"method": "solve_iterative", ...},
-    "recursive": {"method": "solve_recursive", ...},
-}
-```
-
-Create with template: `new_problem.bat 0025_reverse_nodes --wrapper`
-
-</details>
+Create with template: `new_problem.bat 0023_merge_k_lists --multi`
 
 ### 🔀 Flexible Output Validation
 
@@ -784,8 +767,7 @@ neetcode/
 │
 ├── templates/                 # 📄 Problem templates
 │   ├── template_solution.py          # Single solution
-│   ├── template_solution_multi.py    # Multi-solution (one class)
-│   └── template_solution_wrapper.py  # Multi-solution (wrapper pattern)
+│   └── template_solution_multi.py    # Multi-solution (polymorphic)
 │
 ├── .vscode/                   # 🔧 VS Code integration
 │   ├── settings.json          # Python environment settings

README_zh-TW.md

@@ -427,41 +427,53 @@ if __name__ == "__main__":
 
 ### 🚀 多解法效能比較
 
-比較同一題目的多種解法：
+使用**多型模式**比較同一題目的多種解法：
 
 ```python
 # solutions/0023_merge_k_sorted_lists.py
+from _runner import get_solver
 
 SOLUTIONS = {
     "default": {
-        "method": "mergeKLists_heap",
+        "class": "SolutionHeap",
+        "method": "mergeKLists",
         "complexity": "O(N log k)",
         "description": "最小堆方法"
     },
     "divide": {
-        "method": "mergeKLists_divide",
+        "class": "SolutionDivideConquer",
+        "method": "mergeKLists",
         "complexity": "O(N log k)",
         "description": "分治法"
     },
     "greedy": {
-        "method": "mergeKLists_greedy",
+        "class": "SolutionGreedy",
+        "method": "mergeKLists",
         "complexity": "O(kN)",
         "description": "貪婪比較"
     },
 }
 
-class Solution:
-    def mergeKLists_heap(self, lists):
+class SolutionHeap:
+    def mergeKLists(self, lists):
         # 堆實作
         pass
-    
-    def mergeKLists_divide(self, lists):
+
+class SolutionDivideConquer:
+    def mergeKLists(self, lists):
         # 分治實作
         pass
-    
-    def mergeKLists_greedy(self, lists):
+
+class SolutionGreedy:
+    def mergeKLists(self, lists):
         # 貪婪實作
         pass
+
+def solve():
+    # ... 解析輸入 ...
+    solver = get_solver(SOLUTIONS)
+    result = solver.mergeKLists(lists)
+    print(result)
 ```
 
 **執行指令：**
@@ -488,36 +500,7 @@ greedy                  44.82ms   O(kN)           3/3
 ============================================================
 ```
 
-<details>
-<summary><strong>進階：Wrapper 模式（多個類別使用相同方法名）</strong></summary>
-
-當需要多個類別使用相同方法名稱時：
-
-```python
-class SolutionRecursive:
-    def reverseKGroup(self, head, k):
-        pass  # 遞迴實作
-
-class SolutionIterative:
-    def reverseKGroup(self, head, k):
-        pass  # 迭代實作
-
-# Wrapper 函式
-def solve_recursive(head, k):
-    return SolutionRecursive().reverseKGroup(head, k)
-
-def solve_iterative(head, k):
-    return SolutionIterative().reverseKGroup(head, k)
-
-SOLUTIONS = {
-    "default": {"method": "solve_iterative", ...},
-    "recursive": {"method": "solve_recursive", ...},
-}
-```
-
-使用模板建立：`new_problem.bat 0025_reverse_nodes --wrapper`
-
-</details>
+使用模板建立：`new_problem.bat 0023_merge_k_lists --multi`
 
 ### 🔀 彈性輸出驗證
 
@@ -668,8 +651,7 @@ neetcode/
 │
 ├── templates/                 # 📄 題目模板
 │   ├── template_solution.py          # 單一解法
-│   ├── template_solution_multi.py    # 多解法（單一類別）
-│   └── template_solution_wrapper.py  # 多解法（Wrapper 模式）
+│   └── template_solution_multi.py    # 多解法（多型模式）
 │
 ├── .vscode/                   # 🔧 VS Code 整合
 │   ├── settings.json          # Python 環境設定

docs/ARCHITECTURE_MIGRATION.md

@@ -410,7 +410,7 @@ SOLUTIONS = {
 | Phase 1 | Runner infrastructure | ✅ Completed |
 | Phase 2 | Example migrations | ✅ Completed |
 | Phase 3 | Full migration | Pending (scan remaining solutions) |
-| Phase 4 | Documentation | ✅ Completed |
+| Phase 4 | Documentation & Templates | ✅ Completed |
 
 ### Completed Items
 
@@ -419,5 +419,12 @@ SOLUTIONS = {
   - `0027_remove_element.py` - Polymorphic pattern with `SolutionTwoPointers`, `SolutionTwoEnds`
   - `0025_reverse_nodes_in_k_group.py` - Polymorphic pattern with `SolutionIterative`, `SolutionRecursive`
   - `0023_merge_k_sorted_lists.py` - Split into `SolutionHeap`, `SolutionDivideConquer`, `SolutionGreedy`
-- **Phase 4**: Updated test fixtures in `.dev/tests/` to use polymorphic format
+- **Phase 4**: 
+  - Updated test fixtures in `.dev/tests/` to use polymorphic format
+  - Updated `template_solution.py` to use `SOLUTIONS` + `get_solver()`
+  - Updated `template_solution_multi.py` to use polymorphic pattern
+  - Deleted deprecated `template_solution_wrapper.py`
+  - Updated `new_problem.bat` and `new_problem.sh` (removed `--wrapper` option)
+  - Updated `run_tests.bat` to pass all arguments
+  - Created `docs/solution_contract.md` as canonical specification