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/0778-swim-in-rising-water.org

@@ -1,18 +1,69 @@
 #+PROPERTY: STUDY_DECK_02
 * TODO 0778. Swim In Rising Water :hard:
 :PROPERTIES:
-:NEETCODE: [[file:../../roadmap.org::*0778. Swim In Rising Water][Roadmap]]
+:NEETCODE: [[file:../../roadmap.org::*0778. Swim In Rising Water][0778. Swim In Rising Water]]
 :END:
 
+You are given an ~n x n~ integer matrix ~grid~ where each value ~grid[i][j]~ represents the elevation at that point ~(i, j)~.
+
+It starts raining, and water gradually rises over time. At time ~t~, the water level is ~t~, meaning *any* cell with elevation less than equal to ~t~ is submerged or reachable.
+
+You can swim from a square to another 4-directionally adjacent square if and only if the elevation of both squares individually are at most ~t~. You can swim infinite distances in zero time. Of course, you must stay within the boundaries of the grid during your swim.
+
+Return /the minimum time until you can reach the bottom right square /~(n - 1, n - 1)~/ if you start at the top left square /~(0, 0)~.
+
+*Example 1:*
+
+
+#+begin_src
+Input: grid = [[0,2],[1,3]]
+Output: 3
+Explanation:
+At time 0, you are in grid location (0, 0).
+You cannot go anywhere else because 4-directionally adjacent neighbors have a higher elevation than t = 0.
+You cannot reach point (1, 1) until time 3.
+When the depth of water is 3, we can swim anywhere inside the grid.
+#+end_src
+
+
+*Example 2:*
+
+
+#+begin_src
+Input: grid = [[0,1,2,3,4],[24,23,22,21,5],[12,13,14,15,16],[11,17,18,19,20],[10,9,8,7,6]]
+Output: 16
+Explanation: The final route is shown.
+We need to wait until time 16 so that (0, 0) and (4, 4) are connected.
+#+end_src
+
+
+*Constraints:*
+
+ - ~n == grid.length~
+
+ - ~n == grid[i].length~
+
+ - ~1 <= n <= 50~
+
+ - ~0 <= grid[i][j] < n^{2}~
+
+ - Each value ~grid[i][j]~ is *unique*.
+
 ** TODO Approach
 Write your approach here.
 
 ** TODO Python
 #+begin_src python
-
+class Solution:
+    def swimInWater(self, grid: List[List[int]]) -> int:
 #+end_src
 
 ** TODO C++
 #+begin_src cpp
-
+class Solution {
+public:
+    int swimInWater(vector<vector<int>>& grid) {
+        
+    }
+};
 #+end_src