fix: workspace delete mixed-content error via top-level endpoint

- Add top-level DELETE /workspaces/{workspace_id} endpoint (avoids nested path)
- Frontend deleteWorkspace now uses /workspaces/{id}/?force=... (no project/repo needed)
- Update useWorkspaceActions, ProjectsPage, WorkspacesPage to match new signature

Quality gates: ruff clean, tsc --noEmit clean, pytest workspaces API (9 passed, 1 skipped)

apps/web/src/pages/projects.tsx

@@ -124,15 +124,11 @@ export const ProjectsPage = () => {
 		}
 	};
 
-	const handleDeleteWorkspace = async (
-		projectId: string,
-		repoId: string,
-		workspace: WorkspaceSummary,
-	) => {
+	const handleDeleteWorkspace = async (workspace: WorkspaceSummary) => {
 		if (!confirm(`Delete workspace "${workspace.name}"?`)) return;
 		setWorkspaceLoading(workspace.id);
 		try {
-			await deleteWorkspace(projectId, repoId, workspace.id);
+			await deleteWorkspace(workspace.id);
 			reload();
 		} catch (err) {
 			alert(err instanceof Error ? err.message : "Failed to delete workspace");
@@ -187,7 +183,7 @@ export const ProjectsPage = () => {
 								if (action === "sync") {
 									void handleSyncWorkspace(project.id, repoId, workspace);
 								} else if (action === "delete") {
-									void handleDeleteWorkspace(project.id, repoId, workspace);
+									void handleDeleteWorkspace(workspace);
 								}
 							}}
 							workspaceLoading={workspaceLoading}

apps/web/src/pages/workspaces.tsx

@@ -18,12 +18,7 @@ export function WorkspacesPage() {
 	const actions = useWorkspaceActions();
 
 	const handleDelete = async (workspace: Workspace) => {
-		await actions.delete(
-			workspace.project_id,
-			workspace.repo_id,
-			workspace,
-			refresh,
-		);
+		await actions.delete(workspace, refresh);
 	};
 
 	const handleSync = async (workspace: Workspace) => {