docs(docs): add ProblemBadges component, layout slot, and enrich pages with topics/video frontmatter, plus guide placeholders and topic‑landing map.

apps/docs/content/(01-linear-structures)/stack/150-evaluate-reverse-polish-notation.mdx

@@ -2,13 +2,16 @@
 title: '150. Evaluate Reverse Polish Notation'
 description: You are given an array of strings tokens that represents an arithmetic expression in a Reverse Polish Notation
 icon: dot
+topics:
+  - { name: "Array", slug: "array" }
+  - { name: "Math", slug: "math" }
+  - { name: "Stack", slug: "stack" }
+video: "iu0082c4HDE"
 sidebar:
   label: 'Evaluate Reverse Polish Notation'
   badge: 'Medium'
 ---
 
-<Badge variant="accent">Array</Badge>
-
 ### Example 1:
 - Input: `tokens = ["2","1","+","3","*"]`
 - Output: `9`
@@ -69,7 +72,3 @@ class Solution:
 
         return stack[0]
 ```
-
-## Explanation
-
-<YouTube id="iu0082c4HDE" title="Evaluate Reverse Polish Notation - Leetcode 150 - Python" />