[datlechin]

Summary

• Structure view tabs are now Definition, Triggers, DDL (and Parts on ClickHouse). Definition stacks Columns, Indexes, Foreign Keys and Check Constraints on one scrolling page, each with a disclosure triangle, a count, its own table and its own + and − beneath it (HIG: square buttons go beneath their view, never in a status bar; at most six tabs).
• The trailing inspector edits the selected definition as a typed form, each field under its name on one leading edge (checkboxes, pop-ups, a field with a value menu for Type and Default). With nothing selected it shows the table's Comment and options (character set, collation, convert, next AUTO_INCREMENT) above its statistics. The Comment bar and the Options tab are gone.
• Yes/no fields are checkboxes in the grid, empty cells read blank, and rarely used column fields start hidden (Hide Column / Show All Columns brings them back; the choice is kept per section).
• One StructureDefinitionEditor with one StructureSectionAdapter per section replaces the repointed grid and CreateTableGridAdapter; rows are identified by definition id, so selection survives a reload, a sort or a removal.
• The session owns loading, rebaselining and every command; the view only draws. Weak structureActions closures and InspectorRowSource are gone.
• Create Table uses the same page and inspector: Definition and DDL tabs, the name field and its issue list at the top, a Check Constraints section where the engine can add one, Create with Cmd+S or Cmd+Return.
• The data grid gains a fitsRows mode (as tall as its rows, vertical scroll handed to the page).
• Edit > Undo and Redo name the change and dim when there is nothing to undo, in Structure and Create Table.
• File > Discard Changes… discards staged structure or data edits after asking. Preview SQL has a Save Changes button.
• Fixed: a Primary Key edit never changed the table's key; Undo Delete dropped an edit made before the delete; refresh and the post-save reload skipped check constraints; selection moved to another definition after a reload; one failed read blanked every tab and a failed Triggers read said "No Triggers"; MySQL indexes offered a Condition the server drops; a legacy skipSchemaPreview default turned Preview SQL into Save; Preview skipped Save's validation; Create Table's foreign key menus read the sidebar's database; errors showed unlocalized change names; multi-row paste and duplicate took one undo per row; leaving Structure for Data dimmed Save while edits stayed staged; the inspector named every schema row "Column of"; Cmd+Shift+D did nothing in Structure.
• Removed the generic schema-field path from the window inspector (FieldEditorKind.typePicker, .valuePicker, .schemaText and their views).
• Test changed on purpose: TableCommentStatementTests.driverWithoutStatementThrows now expects the localized change name.

Before	After

Test plan

• New: StructureDefinitionEditorTests, StructureChangeManagerStagingTests (primary key staging, rename, delete and Undo Delete, redo), StructureSectionAdapterTests, StructureAvailabilityTests, StructureInspectorFormTests, StructureInspectorPresentationTests, CreateTableDraftCommandTests, StructureCommandRoutingTests, DataGridFittingHeightTests; the old structure suites migrated to the new API.
• Unit plan locally: 27,264 cases, one failure from the intended update below; every suite touched after it re-run green.
• Driven on a MariaDB 13 and a PostgreSQL 17 table in a sandboxed Debug build: Definition page, inspector for the table and for a new column, opening the inspector without moving the page, light and dark.
• UI flows StructureSaveConfirmationUITests, TableChangeReloadUITests and SidebarAddMenuUITests updated to the new identifiers; they run on CI's UI plan.
• Docs: docs(features): document the redesigned Structure tab docs#138.