Add comprehensive E2E tests for materia CLI

- Add pytest and pytest-cov for testing
- Add niquests for modern HTTP/2 support (keep requests for hcloud compatibility)
- Create 13 E2E tests covering CLI, workers, pipelines, and secrets (71% coverage)
- Fix Pulumi ESC environment path (beanflows/prod) and secret key names
- Update GitLab CI to run CLI tests with coverage reporting

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

pyproject.toml

@@ -11,9 +11,10 @@ dependencies = [
     "pyarrow>=20.0.0",
     "python-dotenv>=1.1.0",
     "typer>=0.15.0",
-    "hcloud>=2.3.0",
     "paramiko>=3.5.0",
     "pyyaml>=6.0.2",
+    "niquests>=3.15.2",
+    "hcloud>=2.8.0",
 ]
 
 [project.scripts]
@@ -30,6 +31,8 @@ dev = [
     "pulumi>=3.202.0",
     "pulumi-cloudflare>=6.10.0",
     "pulumi-hcloud>=1.25.0",
+    "pytest>=8.4.2",
+    "pytest-cov>=7.0.0",
     "pyyaml>=6.0.2",
     "ruff>=0.9.9",
 ]