Add solution notes scaffold and sub-heading format

- roadmap.org: problems now have *** Python and *** C++ sub-headings,
  plus Notes: links to per-problem org files
- scaffold-notes.mjs: creates 199 note files in org/cpp/dsa/<topic>/
  with backlinks to roadmap.org
- 18 topic folders under org/cpp/dsa/ for NeetCode 150 problems
- Updated AGENTS.md with new conventions and workflow

org/cpp/dsa/binary-search/0004-median-of-two-sorted-arrays.org

@@ -0,0 +1,8 @@
+* TODO 0004. Median of Two Sorted Arrays :hard:
+:PROPERTIES:
+:NEETCODE: [[../../../../leetcode/out/roadmap.org::*0004. Median of Two Sorted Arrays][Roadmap]]
+:END:
+
+#+begin_src cpp
+
+#+end_src

org/cpp/dsa/binary-search/0033-search-in-rotated-sorted-array.org

@@ -0,0 +1,8 @@
+* TODO 0033. Search In Rotated Sorted Array :medium:
+:PROPERTIES:
+:NEETCODE: [[../../../../leetcode/out/roadmap.org::*0033. Search In Rotated Sorted Array][Roadmap]]
+:END:
+
+#+begin_src cpp
+
+#+end_src

org/cpp/dsa/binary-search/0074-search-a-2d-matrix.org

@@ -0,0 +1,8 @@
+* TODO 0074. Search a 2D Matrix :medium:
+:PROPERTIES:
+:NEETCODE: [[../../../../leetcode/out/roadmap.org::*0074. Search a 2D Matrix][Roadmap]]
+:END:
+
+#+begin_src cpp
+
+#+end_src

org/cpp/dsa/binary-search/0153-find-minimum-in-rotated-sorted-array.org

@@ -0,0 +1,8 @@
+* TODO 0153. Find Minimum In Rotated Sorted Array :medium:
+:PROPERTIES:
+:NEETCODE: [[../../../../leetcode/out/roadmap.org::*0153. Find Minimum In Rotated Sorted Array][Roadmap]]
+:END:
+
+#+begin_src cpp
+
+#+end_src

org/cpp/dsa/binary-search/0704-binary-search.org

@@ -0,0 +1,8 @@
+* TODO 0704. Binary Search :easy:
+:PROPERTIES:
+:NEETCODE: [[../../../../leetcode/out/roadmap.org::*0704. Binary Search][Roadmap]]
+:END:
+
+#+begin_src cpp
+
+#+end_src

org/cpp/dsa/binary-search/0719-find-k-th-smallest-pair-distance.org

@@ -0,0 +1,8 @@
+* TODO 0719. Find K-th Smallest Pair Distance :hard:
+:PROPERTIES:
+:NEETCODE: [[../../../../leetcode/out/roadmap.org::*0719. Find K-th Smallest Pair Distance][Roadmap]]
+:END:
+
+#+begin_src cpp
+
+#+end_src

org/cpp/dsa/binary-search/0875-koko-eating-bananas.org

@@ -0,0 +1,8 @@
+* TODO 0875. Koko Eating Bananas :medium:
+:PROPERTIES:
+:NEETCODE: [[../../../../leetcode/out/roadmap.org::*0875. Koko Eating Bananas][Roadmap]]
+:END:
+
+#+begin_src cpp
+
+#+end_src

org/cpp/dsa/binary-search/0981-time-based-key-value-store.org

@@ -0,0 +1,8 @@
+* TODO 0981. Time Based Key Value Store :medium:
+:PROPERTIES:
+:NEETCODE: [[../../../../leetcode/out/roadmap.org::*0981. Time Based Key Value Store][Roadmap]]
+:END:
+
+#+begin_src cpp
+
+#+end_src

org/cpp/dsa/binary-search/2300-successful-pairs-of-spells-and-potions.org

@@ -0,0 +1,8 @@
+* TODO 2300. Successful Pairs of Spells and Potions :medium:
+:PROPERTIES:
+:NEETCODE: [[../../../../leetcode/out/roadmap.org::*2300. Successful Pairs of Spells and Potions][Roadmap]]
+:END:
+
+#+begin_src cpp
+
+#+end_src