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/archive/PLAN_storefront-module-restructure.md

@@ -47,7 +47,7 @@ Add new rule:
 
 ### Task 1.2: Update validator to check this rule
 
-**File:** `scripts/validate_architecture.py`
+**File:** `scripts/validate/validate_architecture.py`
 
 Add validation for API-007.
 
@@ -340,5 +340,5 @@ After migrated to `app/modules/cart/services/cart_service.py`.
 
 ### Modified Files
 - `app/api/deps.py` (CustomerContext return type)
-- `scripts/validate_architecture.py` (add API-007 check)
+- `scripts/validate/validate_architecture.py` (add API-007 check)
 - All files currently importing from legacy locations