feat: add CI/CD testing infrastructure with test.sh orchestrator

Complete testing system: pyproject.toml (pytest markers), test.sh
orchestrator with auto app start/stop and colorful summary,
pre-push hook, Gitea Actions workflow.

New QA tests: API health (7 endpoints), responsive (3 viewports),
log monitoring (ERROR/ORA-/Traceback detection), real GoMag sync,
PL/SQL package validation, smoke prod (read-only).

Converted test_app_basic.py and test_integration.py to pytest.
Added pytestmark to all existing tests (unit/e2e/oracle).
E2E conftest upgraded: console error collector, screenshot on
failure, auto-detect live app on :5003.

Usage: ./test.sh ci (30s) | ./test.sh full (2-3min)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

api/tests/e2e/test_missing_skus.py

@@ -2,6 +2,8 @@
 import pytest
 from playwright.sync_api import Page, expect
 
+pytestmark = pytest.mark.e2e
+
 
 @pytest.fixture(autouse=True)
 def navigate_to_missing(page: Page, app_url: str):