Fix CI: add test deps (polars, pandas, pyarrow) and coverage

- Add polars, pandas, pyarrow to the tests optional dependency
  group so response tests can run in CI
- Fix .coveragerc: use package_name (omnipath_client) not
  project_name (omnipath-client) so coverage tracks the right
  import path
- CI workflow generates coverage XML and uploads to Codecov

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

Author: deeenes

.coveragerc

@@ -1,12 +1,12 @@
 [paths]
 source =
-    project_name
-    */site-packages/omnipath-client
+    omnipath_client
+    */site-packages/omnipath_client
 
 [run]
 branch = true
 parallel = true
-source = omnipath-client
+source = omnipath_client
 omit = */__init__.py
 
 [report]

pyproject.toml

@@ -53,7 +53,10 @@ tests = [
     "coverage>=6.0",
     "codecov-cli>=10.2.0",
     "diff_cover",
-    "ruff"
+    "ruff",
+    "polars>=0.20.0",
+    "pandas>=1.5",
+    "pyarrow>=10",
 ]
 
 [project.urls]