fix(base): keep editor scroll stable when inline-embed creation completes

The placeholder rendered the full 10-row BaseTableSkeleton (~440px)
while waiting for the create response, then BaseTable mounted, ran its
own queries, and rendered the same 10-row skeleton again until rows
loaded. The actual content for a freshly-created empty base is ~112px
— so the swap shrank the doc by ~330px and on a short page the
browser clamped scrollY past the new doc bottom, manifesting as a
"jump to top of editor."

Two changes to keep the height constant end-to-end:

1. BaseTableSkeleton now accepts a `rows` prop (default 10). The
   placeholder in BaseEmbedView passes `rows={0}` so the skeleton
   matches the height of the eventual empty base shell — header row +
   AddRow button, no fake body rows.

2. The Database slash command now seeds `["bases", id]` and the
   `["base-rows", id, undefined, undefined, undefined]` infinite-query
   cache from the create response (the endpoint already returns the
   full base with properties + views; the typed return was just too
   narrow). BaseTable mounts with baseLoading/rowsLoading already
   false and skips its own skeleton — no transient grow-then-shrink
   between placeholder and final content.

End state: placeholder height ≈ rendered-empty-base height, and no
intermediate skeleton appears while BaseTable is "loading." The
scrollY clamp can't fire because the doc never shrinks.

apps/client/src/features/base/components/base-table-skeleton.tsx

@@ -5,14 +5,24 @@ import classes from "@/features/base/styles/base-table-skeleton.module.css";
 const ROW_NUMBER_WIDTH = 64;
 const COLUMN_WIDTH = 180;
 const COLUMN_COUNT = 6;
-const ROW_COUNT = 10;
+const DEFAULT_ROW_COUNT = 10;
 
 // Deterministic per-cell widths so the skeleton doesn't flicker between
 // renders. Values are rough normal distribution around 55-85 % of cell.
 const CELL_WIDTH_RATIOS = [0.78, 0.62, 0.84, 0.55, 0.71, 0.66];
 const HEADER_WIDTH_RATIOS = [0.42, 0.58, 0.5, 0.64, 0.46, 0.54];
 
-export function BaseTableSkeleton() {
+type BaseTableSkeletonProps = {
+  // Override the body row count. Pass 0 when rendering as the
+  // "creating database" placeholder for a freshly-inserted inline embed
+  // — the eventual empty base has no rows, so a 10-row skeleton would
+  // shrink ~330px on swap and trip the browser's scrollY clamp.
+  rows?: number;
+};
+
+export function BaseTableSkeleton({
+  rows = DEFAULT_ROW_COUNT,
+}: BaseTableSkeletonProps = {}) {
   const gridTemplateColumns = [
     `${ROW_NUMBER_WIDTH}px`,
     ...Array.from({ length: COLUMN_COUNT }, () => `${COLUMN_WIDTH}px`),
@@ -54,7 +64,7 @@ export function BaseTableSkeleton() {
             </div>
           ))}
 
-          {Array.from({ length: ROW_COUNT }).map((_, rowIndex) => (
+          {Array.from({ length: rows }).map((_, rowIndex) => (
             <div key={`row-${rowIndex}`} style={{ display: "contents" }}>
               <div className={gridClasses.cell}>
                 <div className={classes.cellInner}>