fix: Update import statement for client in currency workflow tests

docs/ci-cache-troubleshooting.md

@@ -0,0 +1,27 @@
+# CI Cache Troubleshooting
+
+## Background
+
+The test workflow (`.gitea/workflows/test.yml`) uses the `actions/cache` action to reuse the pip download cache located at `~/.cache/pip`. The cache key now hashes both `requirements.txt` and `requirements-test.txt` so the cache stays aligned with dependency changes.
+
+## Current Observation
+
+Recent CI runs report the following warning when the cache step executes:
+
+```text
+::warning::Failed to restore: getCacheEntry failed: connect ETIMEDOUT 172.17.0.5:40181
+Cache not found for input keys: Linux-pip-<hash>, Linux-pip-
+```
+
+The timeout indicates the runner cannot reach the cache backend rather than a normal cache miss.
+
+## Recommended Follow-Up
+
+- Confirm that the Actions cache service is enabled for the CI environment (Gitea runners require the cache server URL to be provided via `ACTIONS_CACHE_URL` and `ACTIONS_RUNTIME_URL`).
+- Verify network connectivity from the runner to the cache service endpoint and ensure required ports are open.
+- After connectivity is restored, rerun the workflow to allow the cache to be populated and confirm subsequent runs restore the cache without warnings.
+
+## Interim Guidance
+
+- The workflow will proceed without cached dependencies, but package installs may take longer.
+- Keep the cache step in place so it begins working automatically once the infrastructure is configured.

tests/unit/test_currency_workflow.py

@@ -1,4 +1,4 @@
-from tests.unit.conftest import client
+from tests.unit.test_costs import client
 
 
 def test_create_capex_with_currency_code_and_list():