Fix Windows test timeout and restore parallel testing (#2383)

OAuth consent tests were timing out on Windows due to SQLite database
locking when OAuthProxy instances used the default DiskStore without
explicit MemoryStore configuration. Added explicit client_storage=MemoryStore()
to three tests in TestConsentPageServerIcon.

Also restored parallel testing on Windows (--numprocesses auto) which
was previously disabled but is now safe with proper test isolation.

.github/workflows/run-tests.yml

@@ -48,12 +48,7 @@ jobs:
         run: uv sync --upgrade
 
       - name: Run tests (excluding integration and client_process)
-        run: |
-          if [ "${{ matrix.os }}" = "windows-latest" ]; then
-            uv run pytest --inline-snapshot=disable tests -m "not integration and not client_process"
-          else
-            uv run pytest --inline-snapshot=disable tests -m "not integration and not client_process" --numprocesses auto --maxprocesses 4 --dist worksteal
-          fi
+        run: uv run pytest --inline-snapshot=disable tests -m "not integration and not client_process" --numprocesses auto --maxprocesses 4 --dist worksteal
         shell: bash
 
       - name: Run client process tests separately

tests/server/auth/test_oauth_consent_flow.py

@@ -691,6 +691,7 @@ class TestConsentPageServerIcon:
             upstream_client_secret="upstream-secret",
             token_verifier=verifier,
             base_url="https://proxy.example.com",
+            client_storage=MemoryStore(),
             jwt_signing_key="test-secret",
         )
 
@@ -763,6 +764,7 @@ class TestConsentPageServerIcon:
             upstream_client_secret="upstream-secret",
             token_verifier=verifier,
             base_url="https://proxy.example.com",
+            client_storage=MemoryStore(),
             jwt_signing_key="test-secret",
         )
 
@@ -830,6 +832,7 @@ class TestConsentPageServerIcon:
             upstream_client_secret="upstream-secret",
             token_verifier=verifier,
             base_url="https://proxy.example.com",
+            client_storage=MemoryStore(),
             jwt_signing_key="test-secret",
         )