chore: add diagnostic logging around workspace git clone

The workspace creation endpoint returns 500 but the actual error is not
visible. Add explicit error logging when GitService.clone fails and info
logging when git creates a directory name different from the one derived
from the remote URL.

Quality gates:
- pytest tests/unit: 219 passed
- mypy: clean on changed files

apps/api/src/services/shared/workspace_manager.py

@@ -139,7 +139,19 @@ class WorkspaceManager:
                     ssh_key_obj.private_key_encrypted.encode()
                 ).decode()
 
-        await GitService.clone(repo.remote_url, branch, clone_target, ssh_key=ssh_key)
+        try:
+            await GitService.clone(
+                repo.remote_url, branch, clone_target, ssh_key=ssh_key
+            )
+        except Exception as exc:
+            logger.error(
+                "Git clone failed for workspace %s (repo=%s, url=%s): %s",
+                workspace_id,
+                repo.id,
+                repo.remote_url,
+                exc,
+            )
+            raise
 
         expected_path = os.path.join(parent_path, repo_dir_name)
         if not os.path.isdir(expected_path):
@@ -150,6 +162,12 @@ class WorkspaceManager:
                 for entry in os.listdir(parent_path)
                 if os.path.isdir(os.path.join(parent_path, entry))
             ]
+            logger.info(
+                "Workspace %s: expected %s/ but found directories: %s",
+                workspace_id,
+                repo_dir_name,
+                entries,
+            )
             if len(entries) == 1:
                 expected_path = os.path.join(parent_path, entries[0])
             else: