Rename project module and database references: Bookmann → Bookhoard

Core infrastructure changes:
- Update Go module name: bookmann → bookhoard
- Rename database schema references and comments
- Update database column names: bookmann_uuid → bookhoard_uuid
- Rename SQL query functions: GetDeviceCatalogByBookmannUUID → GetDeviceCatalogByBookhoardUUID
- Update configuration defaults

This is part 1 of the project rename to Bookhoard.

database/schema/schema.sql

@@ -1,5 +1,5 @@
--- Consolidated Bookmann Database Schema
--- This file contains the complete current schema for the Bookmann media library management system
+-- Consolidated Bookhoard Database Schema
+-- This file contains the complete current schema for the Bookhoard media library management system
 
 -- Create library types table
 CREATE TABLE library_types (
@@ -848,7 +848,7 @@ CREATE TABLE IF NOT EXISTS collection_items (
 CREATE INDEX IF NOT EXISTS idx_collection_items_collection ON collection_items(collection_id);
 CREATE INDEX IF NOT EXISTS idx_collection_items_media ON collection_items(media_item_id);
 
--- Create device_shelf_mappings table (map Bookmann collections to device-specific shelf names)
+-- Create device_shelf_mappings table (map Bookhoard collections to device-specific shelf names)
 CREATE TABLE IF NOT EXISTS device_shelf_mappings (
     id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
     collection_id UUID NOT NULL REFERENCES collections(id) ON DELETE CASCADE,
@@ -862,7 +862,7 @@ CREATE TABLE IF NOT EXISTS device_shelf_mappings (
 CREATE INDEX IF NOT EXISTS idx_device_shelf_mappings_collection ON device_shelf_mappings(collection_id);
 CREATE INDEX IF NOT EXISTS idx_device_shelf_mappings_device ON device_shelf_mappings(device_id);
 
--- Create device_catalogs table (track OPDS downloads and map Bookmann UUIDs to device ContentIds)
+-- Create device_catalogs table (track OPDS downloads and map Bookhoard UUIDs to device ContentIds)
 CREATE TABLE IF NOT EXISTS device_catalogs (
     id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
     device_id UUID NOT NULL REFERENCES devices(id) ON DELETE CASCADE,