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/2-d-dynamic-programming/0097-interleaving-string.org

@@ -1,18 +1,80 @@
 #+PROPERTY: STUDY_DECK_02
 * TODO 0097. Interleaving String :medium:
 :PROPERTIES:
-:NEETCODE: [[file:../../roadmap.org::*0097. Interleaving String][Roadmap]]
+:NEETCODE: [[file:../../roadmap.org::*0097. Interleaving String][0097. Interleaving String]]
 :END:
 
+Given strings ~s1~, ~s2~, and ~s3~, find whether ~s3~ is formed by an *interleaving* of ~s1~ and ~s2~.
+
+An *interleaving* of two strings ~s~ and ~t~ is a configuration where ~s~ and ~t~ are divided into ~n~ and ~m~ substrings respectively, such that:
+
+ - ~s = s_{1} + s_{2} + ... + s_{n}~
+
+ - ~t = t_{1} + t_{2} + ... + t_{m}~
+
+ - ~|n - m| <= 1~
+
+ - The *interleaving* is ~s_{1} + t_{1} + s_{2} + t_{2} + s_{3} + t_{3} + ...~ or ~t_{1} + s_{1} + t_{2} + s_{2} + t_{3} + s_{3} + ...~
+
+*Note:* ~a + b~ is the concatenation of strings ~a~ and ~b~.
+
+*Example 1:*
+
+
+#+begin_src
+Input: s1 = "aabcc", s2 = "dbbca", s3 = "aadbbcbcac"
+Output: true
+Explanation: One way to obtain s3 is:
+Split s1 into s1 = "aa" + "bc" + "c", and s2 into s2 = "dbbc" + "a".
+Interleaving the two splits, we get "aa" + "dbbc" + "bc" + "a" + "c" = "aadbbcbcac".
+Since s3 can be obtained by interleaving s1 and s2, we return true.
+#+end_src
+
+
+*Example 2:*
+
+
+#+begin_src
+Input: s1 = "aabcc", s2 = "dbbca", s3 = "aadbbbaccc"
+Output: false
+Explanation: Notice how it is impossible to interleave s2 with any other string to obtain s3.
+#+end_src
+
+
+*Example 3:*
+
+
+#+begin_src
+Input: s1 = "", s2 = "", s3 = ""
+Output: true
+#+end_src
+
+
+*Constraints:*
+
+ - ~0 <= s1.length, s2.length <= 100~
+
+ - ~0 <= s3.length <= 200~
+
+ - ~s1~, ~s2~, and ~s3~ consist of lowercase English letters.
+
+*Follow up:* Could you solve it using only ~O(s2.length)~ additional memory space?
+
 ** TODO Approach
 Write your approach here.
 
 ** TODO Python
 #+begin_src python
-
+class Solution:
+    def isInterleave(self, s1: str, s2: str, s3: str) -> bool:
 #+end_src
 
 ** TODO C++
 #+begin_src cpp
-
+class Solution {
+public:
+    bool isInterleave(string s1, string s2, string s3) {
+        
+    }
+};
 #+end_src