OpenSquilla 0.5.1 maintenance release

🦐 OpenSquilla 0.5.1 is a maintenance release for the 0.5 stable line — mostly stability and polish, with a handful of small features layered on top. Upgrading from 0.5.0 preserves your existing config, chats, Agents, memory, and scheduled jobs.

🗂️ Plan mode, projects & artifacts — durable Plan mode keeps plans visible and actionable across the whole turn; project workspaces get a first-class setup flow, clearer chat activity, and safer sandbox routing; artifact previews gain richer browser-grade rendering and a more extensible workbench; and desktop deep links open the intended destination directly.

🖥️ Startup & profile recovery — Desktop consolidates legacy recovery profiles into the primary one without silently merging two active profiles; Windows can recoverably import an existing profile and resolves sandbox setup paths correctly; first-install provider/model routing state is retained; and session deletion waits for the runtime to quiesce.

🎛️ Control console & providers — cleaner chat and provider settings, improved assistant activity, and stable Skills navigation; Qwen Token Plan and custom Anthropic-compatible providers are now first-class choices; channel-admin approvals are consistent again and gateway self-termination is refused.

⏰ Scheduled tasks — Full mode now behaves consistently across Web, CLI, TaskRuntime and Cron for the local owner; owner-created Cron jobs keep their execution mode; and tool-created Cron jobs use atomic idempotency, so a single model response can no longer spawn dozens of identical jobs.

Upgrading: close any running app or gateway, install with one of the pinned downloads below, and restart. Existing config and session data are preserved.