feat(ebooks): add ISBN normalization and graceful library requirement handling

- Increase ISBN column from VARCHAR(13) to VARCHAR(17) to support ISBN-13 with hyphens
- Add normalize_isbn() database function to automatically remove hyphens and spaces
- Create trigger to auto-normalize ISBNs on INSERT/UPDATE operations
- Update all Ebook and MediaItem queries to use ISBN normalization
- Add GetEbookLibraryID query to check for existing ebook libraries
- Add graceful error handling when no ebook library exists
- Return helpful error message: 'no ebook library found. Please create an ebook library first'
- Create comprehensive tests for ISBN normalization and library selection
- Add Bruno test files for various ISBN formats and error scenarios
- Update documentation with ISBN normalization details

bruno/ebooks/Create Ebook.bru

@@ -14,7 +14,7 @@ body:json {
   {
     "title": "Sample Ebook Title",
     "author": "Author Name",
-    "isbn": "978-0123456789",
+    "isbn": "9780123456789",
     "description": "A sample ebook description",
     "file_path": "/path/to/ebook.epub",
     "file_size": 1048576,
@@ -37,19 +37,19 @@ settings {
 
 docs {
   ## Create Ebook
-  
+
   Creates a new ebook entry in the database.
-  
+
   **Method:** POST
-  
+
   **Endpoint:** /api/ebooks
-  
+
   **Authentication:** Required (Admin only)
-  
+
   **Request Body:** JSON object with:
   - `title` (string, required): Ebook title (1-500 characters)
   - `author` (string, optional): Author name
-  - `isbn` (string, optional): ISBN number
+  - `isbn` (string, optional): ISBN number (will be normalized to remove hyphens and spaces)
   - `description` (string, optional): Ebook description
   - `file_path` (string, required): Path to ebook file
   - `file_size` (integer, required): File size in bytes
@@ -62,19 +62,26 @@ docs {
   - `date_published` (string, optional): Publication date (YYYY-MM-DD)
   - `publisher` (string, optional): Publisher name
   - `contributors` (string, optional): Contributors list
-  
+
   **Response:** Complete ebook object with all fields
-  
+
   **Status Codes:**
   - 201: Ebook created successfully
-  - 400: Bad request (invalid data)
+  - 400: Bad request (invalid data, or no ebook library exists)
   - 401: Unauthorized
   - 403: Forbidden (admin access required)
   - 500: Internal server error
-  
+
   **Features:**
   - Admin-only endpoint for creating ebooks
   - Full validation of required fields
   - Supports all ebook metadata fields
+  - ISBN normalization: automatically removes hyphens and spaces (e.g., "978-0-12345-678-9" becomes "9780123456789")
+  - Requires an existing ebook library to create ebooks
   - Associates ebook with creating admin user
+
+  **ISBN Formats Supported:**
+  - ISBN-13: `9780123456789` or `978-0-12345-678-9` or `978-0123456789`
+  - ISBN-10: `0123456789` or `0-12345-678-9`
+  - All formats are automatically normalized (hyphens and spaces removed)
 }