Fixes #649, #628, #629, and #599.

Changes

• Tree: Correct VscTreeSelectEvent.detail to match the emitted VscodeTreeItem[]; let unhandled Escape key events bubble normally.
• Table: Preserve user-resized widths across unchanged columns assignments and replaced body rows. A divider drag calculates from the widths at gesture start, so moving it back restores the original distribution; movement clamps at the shrinkable width available on the opposite side. Default and per-column minimum widths are now applied correctly. The resizable demo includes a trigger for reassigning the initial columns.
• Scrollable: Make the shadow opt-in; it is rendered only when the shadow property/attribute is enabled.

Table Resize API

• Set resizable to enable divider dragging; it is false by default.
• Use columns for initial widths, as a property array or JSON-encoded attribute. Width entries support pixel-like numeric values, px, %, and auto; auto columns divide the remaining table width. Reassigning unchanged values does not reset user-resized widths.
• Set table-wide min-column-width as the fallback floor for columns without an explicit header minimum. It defaults to 50px; supported size forms include numeric/pixel-like values, px, and %.
• Set min-width on an individual vscode-table-header-cell to override the table fallback for that column. An explicitly authored min-width="0" opts that column out of a non-zero fallback.
• Set delayed-resizing to defer body-cell width updates until the drag ends; otherwise body cells track the resize during the drag.
• Read current widths from the read-only columnWidths getter; it returns percentages in header order.

Guarantees And Limits

• During resizing, a column being shrunk will not be taken below its configured minimum when the minimums are mutually satisfiable within the table width. A drag beyond available shrink capacity is clamped rather than collapsing columns below their minimum or pushing their width out of the layout.
• Reversing the pointer movement within the same drag restores the widths from the start of that gesture. Current widths persist when unchanged columns values are reassigned and when body rows are replaced.
• Minimums constrain resize operations; they do not automatically expand an initially configured column that is already narrower than its minimum. The combined minimum widths should fit within the table width, or there is no layout that can satisfy every minimum.

Validation

TypeScript build passed. Affected scrollable, table, and tree suites: 67 passed, 0 failed, 2 skipped. Prettier, ESLint, and git diff --check passed.