Rename project documentation: Bookmann → Bookhoard

Documentation updates:
- Update README.md title and all references
- Update PROJECT_GUIDELINES.md title and guidelines
- Update all documentation files in docs/ directory
- Update device setup guides (Kobo, KOReader)
- Update API and architecture documentation
- Update completion summaries and progress reports

This is part 5 of the project rename to Bookhoard.

docs/SYNC_USER_GUIDE.md

@@ -1,4 +1,4 @@
-# Bookmann Universal Sync - User Guide
+# Bookhoard Universal Sync - User Guide
 
 ## Table of Contents
 1. [What is Universal Sync?](#what-is-universal-sync)
@@ -13,7 +13,7 @@
 
 ## What is Universal Sync?
 
-**Universal Sync** is Bookmann's cross-platform synchronization system that keeps your reading progress, highlights, and notes in sync across all your devices - automatically and in real-time.
+**Universal Sync** is Bookhoard's cross-platform synchronization system that keeps your reading progress, highlights, and notes in sync across all your devices - automatically and in real-time.
 
 ### Key Features
 
@@ -55,9 +55,9 @@
 
 ### Prerequisites
 
-1. **Bookmann Server** - Self-hosted instance running and accessible
-2. **Network Connection** - Devices must be able to reach your Bookmann server
-3. **User Account** - Created and logged in to Bookmann web interface
+1. **Bookhoard Server** - Self-hosted instance running and accessible
+2. **Network Connection** - Devices must be able to reach your Bookhoard server
+3. **User Account** - Created and logged in to Bookhoard web interface
 
 ### Quick Start
 
@@ -76,11 +76,11 @@
 1. **On Your Device**:
    - Open your reading app (KOReader/Kobo)
    - Navigate to sync settings
-   - Find "Bookmann Sync" or "Calibre Sync"
+   - Find "Bookhoard Sync" or "Calibre Sync"
    - Copy your device identifier (hardware ID)
 
 2. **In Your Browser**:
-   - Go to your Bookmann server
+   - Go to your Bookhoard server
    - Log in with your account
    - Navigate to **Settings → Devices**
    - Click **Register New Device**
@@ -102,7 +102,7 @@
 
 1. **From Your Device**:
    - Navigate to sync settings
-   - Select "Bookmann Sync"
+   - Select "Bookhoard Sync"
    - Enter server URL: `https://bookmann.example.com`
    - Click "Register Device"
    - Device will display registration code