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/advanced-graphs/0332-reconstruct-itinerary.org

@@ -1,18 +1,65 @@
 #+PROPERTY: STUDY_DECK_02
 * TODO 0332. Reconstruct Itinerary :hard:
 :PROPERTIES:
-:NEETCODE: [[file:../../roadmap.org::*0332. Reconstruct Itinerary][Roadmap]]
+:NEETCODE: [[file:../../roadmap.org::*0332. Reconstruct Itinerary][0332. Reconstruct Itinerary]]
 :END:
 
+You are given a list of airline ~tickets~ where ~tickets[i] = [from_{i}, to_{i}]~ represent the departure and the arrival airports of one flight. Reconstruct the itinerary in order and return it.
+
+All of the tickets belong to a man who departs from ~"JFK"~, thus, the itinerary must begin with ~"JFK"~. If there are multiple valid itineraries, you should return the itinerary that has the smallest lexical order when read as a single string.
+
+ - For example, the itinerary ~["JFK", "LGA"]~ has a smaller lexical order than ~["JFK", "LGB"]~.
+
+You may assume all tickets form at least one valid itinerary. You must use all the tickets once and only once.
+
+*Example 1:*
+
+
+#+begin_src
+Input: tickets = [["MUC","LHR"],["JFK","MUC"],["SFO","SJC"],["LHR","SFO"]]
+Output: ["JFK","MUC","LHR","SFO","SJC"]
+#+end_src
+
+
+*Example 2:*
+
+
+#+begin_src
+Input: tickets = [["JFK","SFO"],["JFK","ATL"],["SFO","ATL"],["ATL","JFK"],["ATL","SFO"]]
+Output: ["JFK","ATL","JFK","SFO","ATL","SFO"]
+Explanation: Another possible reconstruction is ["JFK","SFO","ATL","JFK","ATL","SFO"] but it is larger in lexical order.
+#+end_src
+
+
+*Constraints:*
+
+ - ~1 <= tickets.length <= 300~
+
+ - ~tickets[i].length == 2~
+
+ - ~from_{i}.length == 3~
+
+ - ~to_{i}.length == 3~
+
+ - ~from_{i}~ and ~to_{i}~ consist of uppercase English letters.
+
+ - ~from_{i} != to_{i}~
+
 ** TODO Approach
 Write your approach here.
 
 ** TODO Python
 #+begin_src python
-
+class Solution:
+    def findItinerary(self, tickets: List[List[str]]) -> List[str]:
 #+end_src
 
 ** TODO C++
 #+begin_src cpp
-
+class Solution {
+public:
+    vector<string> findItinerary(vector<vector<string>>& tickets) {
+        
+    }
+};
 #+end_src