feat: add Atom-of-Thought (AoT) strategy and prompt definition

## CHANGES

- add new aot.json for Atom-of-Thought (AoT) prompting
- define AoT strategy description and detailed prompt instructions
- update strategies.json to include AoT in available strategies list
- ensure AoT strategy appears alongside CoD, CoT, and LTM options

strategies/aot.json

@@ -0,0 +1,4 @@
+{
+    "description": "Atom-of-Thought (AoT) Prompting",
+    "prompt": "To solve this problem, break it down into the smallest independent 'atomic' sub-problems. For each atomic sub-problem: 1. Label it as 'Atom X: [brief description]' 2. Solve that specific subproblem completely 3. Make sure each atom can be solved independently. After solving all atomic sub-problems, provide a synthesis that combines them into a final answer. Return the final answer in the required format."
+}

web/static/strategies/strategies.json

@@ -1,4 +1,5 @@
 [
+  { "name": "aot", "description": "Atom-of-Thought (AoT)" },
   { "name": "cod", "description": "Chain-of-Draft (CoD)" },
   { "name": "cot", "description": "Chain-of-Thought (CoT) Prompting" },
   { "name": "ltm", "description": "Least-to-Most Prompting" },