praisonai-platform: Label endpoints accept any label_id and any issue_id without workspace ownership check, cross-workspace label edit/delete and issue-label-link IDOR

PraisonAI Platform is the platform layer for the PraisonAI multi-agent teams system. Versions prior to 0.1.4 have an Insecure Direct Object Reference. Five label endpoints — `PATCH /workspaces/{workspace_id}/labels/{label_id}`, `DELETE .../labels/{label_id}`, `POST .../issues/{issue_id}/labels/{label_id}`, `DELETE .../issues/{issue_id}/labels/{label_id}`, `GET .../issues/{issue_id}/labels` — gate access on `require_workspace_member(workspace_id)` only and pass URL-supplied `label_id` and `issue_id` straight through to `LabelService` without verifying either belongs to the workspace. PraisonAI Platform version 0.1.4 patches the issue.