fix(structure): refresh picks up external schema changes (#1281)

[datlechin]

Summary

Closes #1281.

The user-visible bug had two layers behind one symptom (Structure tab not refreshing after an external DDL change):

• Cell rendering cache. DataGridCoordinator.displayCache keys cached cell text by row.id, but TableRows.from(queryRows:...) assigns positional ids (.existing(index)). When external DDL changes a cell's underlying value without changing row count, the cache hits and tableView.reloadData() returns the stale text. The Structure → Columns sub-tab was the most visible victim. Fix: thread ChangeManaging.reloadVersion into DataGridUpdateSnapshot. When that version differs, applyStructuralUpdate invalidates the display cache and forces a full reload. No call-site change — every existing consumer already passes an AnyChangeManager that bumps reloadVersion on every mutation.
• Loaded-tab cache. reloadAllTabs() never cleared loadedTabs, so DDL/FK sub-tabs the user had previously visited rendered stale state on next switch. Also ClickHousePartsView never subscribed to AppCommands.shared.refreshData, so ⌘R didn't reach it. Fix: clear loadedTabs at the top of reloadAllTabs(), and wire Parts to the refresh signal.

Test plan

• ClickHouse: external ALTER TABLE x RENAME COLUMN a TO b → ⌘R on Structure → Columns sub-tab shows b immediately, no tab switch needed.
• Same scenario → switch to DDL sub-tab → generated CREATE TABLE shows b.
• Parts sub-tab: external INSERT creates a new part → ⌘R → Parts list updates.
• Cell edit (Data tab): edit a cell, Tab away → cell shows edited value.
• Cell edit (Create Table dialog): rename a column in the builder → grid reflects the rename.
• State preservation: type in Filter, sort a column, ⌘R → both persist.
• Large Data tab query: run a query that returns thousands of rows, ⌘R → no visible flicker or slowdown beyond previous behavior.