feat: populate note files with problem descriptions and code stubs

Add populate-notes.mjs that fetches problem descriptions and
Python/C++ code stubs from LeetCode's GraphQL API. Populated
all 197 NeetCode 150 note files with:
- Problem description (examples, constraints)
- Python code stub (function signature)
- C++ code stub (function signature + includes)

API responses cached in leetcode/.cache/leetcode/ for instant re-runs.

org/study_deck_02/dsa/trees/1448-count-good-nodes-in-binary-tree.org

@@ -1,18 +1,89 @@
 #+PROPERTY: STUDY_DECK_02
 * TODO 1448. Count Good Nodes In Binary Tree :medium:
 :PROPERTIES:
-:NEETCODE: [[file:../../roadmap.org::*1448. Count Good Nodes In Binary Tree][Roadmap]]
+:NEETCODE: [[file:../../roadmap.org::*1448. Count Good Nodes In Binary Tree][1448. Count Good Nodes In Binary Tree]]
 :END:
 
+Given a binary tree ~root~, a node /X/ in the tree is named *good* if in the path from root to /X/ there are no nodes with a value /greater than/ X.
+
+Return the number of *good* nodes in the binary tree.
+
+*Example 1:*
+
+**
+
+
+#+begin_src
+Input: root = [3,1,4,3,null,1,5]
+Output: 4
+Explanation: Nodes in blue are good.
+Root Node (3) is always a good node.
+Node 4 -> (3,4) is the maximum value in the path starting from the root.
+Node 5 -> (3,4,5) is the maximum value in the path
+Node 3 -> (3,1,3) is the maximum value in the path.
+#+end_src
+
+
+*Example 2:*
+
+**
+
+
+#+begin_src
+Input: root = [3,3,null,4,2]
+Output: 3
+Explanation: Node 2 -> (3, 3, 2) is not good, because "3" is higher than it.
+#+end_src
+
+
+*Example 3:*
+
+
+#+begin_src
+Input: root = [1]
+Output: 1
+Explanation: Root is considered as good.
+#+end_src
+
+
+*Constraints:*
+
+ - The number of nodes in the binary tree is in the range ~[1, 10^5]~.
+
+ - Each node's value is between ~[-10^4, 10^4]~.
+
 ** TODO Approach
 Write your approach here.
 
 ** TODO Python
 #+begin_src python
-
+# Definition for a binary tree node.
+# class TreeNode:
+#     def __init__(self, val=0, left=None, right=None):
+#         self.val = val
+#         self.left = left
+#         self.right = right
+class Solution:
+    def goodNodes(self, root: TreeNode) -> int:
 #+end_src
 
 ** TODO C++
 #+begin_src cpp
-
+/**
+ * Definition for a binary tree node.
+ * struct TreeNode {
+ *     int val;
+ *     TreeNode *left;
+ *     TreeNode *right;
+ *     TreeNode() : val(0), left(nullptr), right(nullptr) {}
+ *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
+ *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
+ * };
+ */
+class Solution {
+public:
+    int goodNodes(TreeNode* root) {
+        
+    }
+};
 #+end_src