Fix chapter numbering to be relative within each part

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: testac974

book/TABLE_OF_CONTENTS.md

@@ -69,7 +69,7 @@
 
 ## Part 2
 
-### Chapter 3: From Brainstorm to Product Brief
+### Chapter 1: From Brainstorm to Product Brief
 
 *[View Chapter](./part2-playbook/03-brainstorm-to-brief.md)*
 
@@ -87,7 +87,7 @@ for search and navigation purposes. To be written during drafting.]
 
 ## Part 4
 
-### Chapter 5: Implementing the MVP
+### Chapter 1: Implementing the MVP
 
 *[View Chapter](./part4-example/05-implementing-mvp.md)*
 

book/part2-playbook/03-brainstorm-to-brief.md

@@ -1,7 +1,7 @@
 ---
 title: "From Brainstorm to Product Brief"
 part: 2
-chapter: 3
+chapter: 1
 version: "0.1"
 date: "2025-12-24"
 status: "draft"

book/part4-example/05-implementing-mvp.md

@@ -1,7 +1,7 @@
 ---
 title: "Implementing the MVP"
 part: 4
-chapter: 5
+chapter: 1
 version: "0.1"
 date: "2025-12-24"
 status: "draft"