refactor: remove GitLab CI config and docs after full Gitea migration

- Delete .gitlab-ci.yml (replaced by .gitea/workflows/ci.yml)
- Delete docs/deployment/gitlab.md (superseded by gitea.md)
- Update audit rules to reference .gitea/workflows/*.yml
- Update validate_audit.py to check Gitea CI paths
- Clean up GitLab references in gitea.md, mkdocs.yml, .dockerignore
- Mark IPv6 AAAA records as completed in hetzner docs

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

.audit-rules/change_management.yaml

@@ -55,7 +55,7 @@ rules:
       type: file_exists
       paths:
         - ".github/PULL_REQUEST_TEMPLATE.md"
-        - ".gitlab/merge_request_templates/*.md"
+        - "CONTRIBUTING.md"
       message: "Pull request template recommended"
 
   - id: CHANGE-REV-002
@@ -74,7 +74,6 @@ rules:
       type: file_exists
       paths:
         - ".github/CODEOWNERS"
-        - "CODEOWNERS"  # GitLab uses root CODEOWNERS or .gitlab/CODEOWNERS
         - "CODEOWNERS"
       message: "Consider defining code owners for critical paths"
 
@@ -91,7 +90,7 @@ rules:
       paths:
         - ".github/workflows/ci.yml"
         - ".github/workflows/test.yml"
-        - ".gitlab-ci.yml"
+        - ".gitea/workflows/*.yml"
       message: "CI workflow for automated testing required"
 
   - id: CHANGE-CI-002
@@ -102,7 +101,7 @@ rules:
       type: pattern_recommended
       paths:
         - ".github/workflows/*.yml"
-        - ".gitlab-ci.yml"
+        - ".gitea/workflows/*.yml"
       patterns:
         - "security|bandit|safety|snyk|trivy"
       message: "Consider security scanning in CI pipeline"
@@ -115,7 +114,7 @@ rules:
       type: pattern_required
       paths:
         - ".github/workflows/*.yml"
-        - ".gitlab-ci.yml"
+        - ".gitea/workflows/*.yml"
       patterns:
         - "ruff|flake8|pylint|mypy|lint"
       message: "Code quality checks required in CI"
@@ -146,7 +145,7 @@ rules:
       paths:
         - ".github/workflows/release.yml"
         - ".github/workflows/deploy.yml"
-        - ".gitlab-ci.yml"
+        - ".gitea/workflows/*.yml"
         - "Dockerfile"
       message: "Automated deployment process recommended"
 
@@ -199,7 +198,7 @@ rules:
       paths:
         - "Dockerfile"
         - ".github/workflows/*.yml"
-        - ".gitlab-ci.yml"
+        - ".gitea/workflows/*.yml"
       patterns:
         - "tag|version|:v"
       message: "Container image versioning recommended"