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>

.gitlab-ci.yml

@@ -79,7 +79,7 @@ architecture:
     - pip install uv
     - uv sync --frozen
   script:
-    - .venv/bin/python scripts/validate_architecture.py
+    - .venv/bin/python scripts/validate/validate_architecture.py
   rules:
     - if: $CI_PIPELINE_SOURCE == "merge_request_event"
     - if: $CI_COMMIT_BRANCH == $CI_DEFAULT_BRANCH
@@ -106,7 +106,7 @@ audit:
     - pip install uv
     - uv sync --frozen
   script:
-    - .venv/bin/python scripts/validate_audit.py
+    - .venv/bin/python scripts/validate/validate_audit.py
   allow_failure: true
   rules:
     - if: $CI_PIPELINE_SOURCE == "merge_request_event"