ui(motion): morph workspace object / explorer switches

[ZhuchkaTriplesix]

Parent

Part of epic #477 (fluid motion follow-ups).

Problem

workspace_panel morphs empty ↔ connected via QueryaSwitchingBody, but selecting a table / routine / Redis DB / Mongo collection hard-cuts the active child. This is the largest perceived fluidity hole after shell polish.

Proposal

Wrap stats↔explorer and home↔table/routine (and equivalent MySQL/SQLite/Ext paths) in QueryaSwitchingBody or keyed QueryaFadeSlide, same pattern as empty↔active.

Files (starting points)

• lib/features/main_screen/workspace_panel.dart
• Driver homes that swap object workspaces (PG/MySQL/SQLite/Ext/Redis/Mongo)

Acceptance

• Opening a sidebar object morphs into the object view (no hard-cut)
• Returning to connection home / stats morphs back
• Respects Full / Reduced / Off via QueryaMotionScope
• Does not animate virtualized result rows
• Widget test or existing workspace test covers keyed morph without crash

[ZhuchkaTriplesix]

Shipped on dev (PR targeted dev, so auto-close did not fire). See related merged PRs.