refactor(scripts): reorganize scripts/ into seed/ and validate/ subfolders

Move 9 init/seed scripts into scripts/seed/ and 7 validation scripts
(+ validators/ subfolder) into scripts/validate/ to reduce clutter in
the root scripts/ directory. Update all references across Makefile,
CI/CD configs, pre-commit hooks, docs (~40 files), and Python imports.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docs/features/cms-implementation-guide.md

@@ -217,7 +217,7 @@ Then update the footer template:
 
 ### 7. Create Default Platform Pages (Script)
 
-Create `scripts/create_default_content_pages.py`:
+Create `scripts/seed/create_default_content_pages.py`:
 
 ```python
 #!/usr/bin/env python3
@@ -347,7 +347,7 @@ if __name__ == "__main__":
 
 Run it:
 ```bash
-python scripts/create_default_content_pages.py
+python scripts/seed/create_default_content_pages.py
 ```
 
 ## Testing

docs/features/content-management-system.md

@@ -505,7 +505,7 @@ Standard slugs to implement:
 
 1. **Create Platform Defaults**:
 ```bash
-python scripts/create_default_content_pages.py
+python scripts/seed/create_default_content_pages.py
 ```
 
 2. **Migrate Existing Static Templates**:

docs/features/email-system.md

@@ -171,7 +171,7 @@ Templates use Jinja2 syntax for variable interpolation:
 Run the seed script to populate default templates:
 
 ```bash
-python scripts/seed_email_templates.py
+python scripts/seed/seed_email_templates.py
 ```
 
 This creates templates for:
@@ -302,7 +302,7 @@ Test coverage includes:
 app/services/email_service.py    # Email service with provider abstraction
 models/database/email.py         # EmailTemplate and EmailLog models
 app/core/config.py               # Email configuration settings
-scripts/seed_email_templates.py  # Template seeding script
+scripts/seed/seed_email_templates.py  # Template seeding script
 ```
 
 ### Provider Abstraction

docs/features/platform-homepage.md

@@ -193,7 +193,7 @@ Manage all platform content pages from a single interface:
 
 ```bash
 # Create all default platform pages
-python scripts/create_platform_pages.py
+python scripts/seed/create_platform_pages.py
 ```
 
 This creates:
@@ -568,7 +568,7 @@ return templates.TemplateResponse(
 **Solutions:**
 1. Run seeder script:
    ```bash
-   python scripts/create_platform_pages.py
+   python scripts/seed/create_platform_pages.py
    ```
 
 2. Verify page exists: