fix: add file: prefix to org-mode links for Emacs resolution

Emorg org-mode requires [[file:path]] syntax for file links to be
clickable. Updated both extract.mjs and scaffold-notes.mjs generators,
and fixed all 200 existing note files.

org/study_deck_02/dsa/tries/0208-implement-trie-prefix-tree.org

@@ -1,7 +1,7 @@
 * TODO 0208. Implement Trie Prefix Tree :medium:
 #+PROPERTY: STUDY_DECK_02
 :PROPERTIES:
-:NEETCODE: [[../../roadmap.org::*0208. Implement Trie Prefix Tree][Roadmap]]
+:NEETCODE: [[file:../../roadmap.org::*0208. Implement Trie Prefix Tree][Roadmap]]
 :END:
 
 ** TODO Approach

org/study_deck_02/dsa/tries/0211-design-add-and-search-words-data-structure.org

@@ -1,7 +1,7 @@
 * TODO 0211. Design Add And Search Words Data Structure :medium:
 #+PROPERTY: STUDY_DECK_02
 :PROPERTIES:
-:NEETCODE: [[../../roadmap.org::*0211. Design Add And Search Words Data Structure][Roadmap]]
+:NEETCODE: [[file:../../roadmap.org::*0211. Design Add And Search Words Data Structure][Roadmap]]
 :END:
 
 ** TODO Approach

org/study_deck_02/dsa/tries/0212-word-search-ii.org

@@ -1,7 +1,7 @@
 * TODO 0212. Word Search II :hard:
 #+PROPERTY: STUDY_DECK_02
 :PROPERTIES:
-:NEETCODE: [[../../roadmap.org::*0212. Word Search II][Roadmap]]
+:NEETCODE: [[file:../../roadmap.org::*0212. Word Search II][Roadmap]]
 :END:
 
 ** TODO Approach

org/study_deck_02/dsa/tries/1166-design-file-system.org

@@ -1,7 +1,7 @@
 * TODO 1166. Design File System :medium:
 #+PROPERTY: STUDY_DECK_02
 :PROPERTIES:
-:NEETCODE: [[../../roadmap.org::*1166. Design File System][Roadmap]]
+:NEETCODE: [[file:../../roadmap.org::*1166. Design File System][Roadmap]]
 :END:
 
 ** TODO Approach