feat(editor): allow reordering tabs via drag-and-drop

[maximumbreak]

Demo

Screen.Recording.2569-07-23.at.17.30.11.mov

Summary

• Console, table, query-builder, and notebook tabs all share one tab bar and one flat tabs array, so tabs of any type can now be dragged to reorder — no artificial restriction to console-only.
• Reordering is scoped to the active connection: dragging only reshuffles that connection's own tabs; tabs belonging to other connections keep their original slots in the underlying array.
• Follows the existing native HTML5 drag-and-drop pattern already used for notebook cell reordering (src/utils/notebookDnd.ts) — same auto-scroll behavior near the edges, same gap-based insertion model, default browser drag ghost with reduced opacity on the source tab, and an insertion-line indicator showing where the tab will land.
• No new persistence code: the existing tab-save effect (EditorProvider) already writes to preferences.json whenever tabs changes, so the new order is picked up automatically.

Changes

• src/utils/tabDnd.ts (new): moveTab() — pure, connection-scoped array reorder.
• tests/utils/tabDnd.test.ts (new): unit tests covering forward/backward moves, first/last position, no-ops, unknown ids, out-of-range input, and the multi-connection interleaving case.
• src/contexts/EditorContext.ts / EditorProvider.tsx: added reorderTab(fromTabId, insertAt).
• src/pages/Editor.tsx: wired up draggable/drag handlers on tab elements, container-level drop + auto-scroll, and the insertion-line indicator.

Test plan

• pnpm typecheck — clean
• pnpm lint — clean
• pnpm test — 170 files / 3121 tests passing
• Manually verified in pnpm tauri dev against a live Postgres connection
• Reviewer: drag tabs across a few connections, confirm order persists after switching away and back

[debba]

Looks promising, it's something we'd like to integrate.
I will test it ASAP