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/development/creating-modules.md

@@ -501,7 +501,7 @@ Existing modules (CMS, billing, marketplace, etc.) currently have their migratio
 Run the architecture validator to check your module:
 
 ```bash
-python scripts/validate_architecture.py
+python scripts/validate/validate_architecture.py
 ```
 
 ### Validation Rules
@@ -538,7 +538,7 @@ python scripts/validate_architecture.py
 - [ ] Create locales (en, de, fr, lu)
 - [ ] Create `config.py` if module needs environment settings (optional)
 - [ ] Create `migrations/versions/` with `__init__.py` files if module has database tables
-- [ ] Run `python scripts/validate_architecture.py`
+- [ ] Run `python scripts/validate/validate_architecture.py`
 - [ ] Test routes are accessible
 
 ### No Framework Changes Needed