Address #133 review: the toolkit has one home now

The `embedded` prop was always true, which left the card branch dead;
the component is simply the rail's tab now. The focus comment is one
line, and the default tab says why it is Plot and not the first tab.

Co-Authored-By: Claude Fable 5 <[email protected]>

web/src/editor/Toolkit.tsx

@@ -14,18 +14,18 @@ import { useEditorStore } from './store'
 import type { EditorObject } from './types'
 
 /**
- * The desktop editor's toolkit. Out of focus: the seven object kinds as pill
- * rows — click to arm (then click the plan), or drag one straight onto it. In a
- * focused bed it swaps to the plant list with a search, same arm/drag behavior,
- * plus the bed's bulk tools (fill, clear, scan a packet).
+ * The desktop editor's toolkit, the rail's first tab. Out of focus: the seven
+ * object kinds as pill rows — click to arm (then click the plan), or drag one
+ * straight onto it. In a focused bed it swaps to the plant list with a search,
+ * same arm/drag behavior, plus the bed's bulk tools (fill, clear, scan a
+ * packet).
  *
- * It started life as the workspace's left card (the handoff's layout) and now
- * lives as the first tab of the rail, so the plan and the rail get the width
- * the card took. `embedded` is that mode: no card chrome of its own, and no
- * "Toolkit" heading — the tab is the heading.
+ * It started life as the workspace's left card (the handoff's layout) and
+ * moved into the rail so the plan and the rail get the width the card took;
+ * the rail's tab body provides the card chrome and the scrolling, and the tab
+ * is the heading.
  */
 export function Toolkit({
-  embedded = false,
   unit,
   plants,
   plantings,
@@ -40,7 +40,6 @@ export function Toolkit({
   onClear,
   onScan,
 }: {
-  embedded?: boolean
   unit: UnitPref
   plants: Plant[]
   plantings: EditorPlanting[]
@@ -62,10 +61,9 @@ export function Toolkit({
   const [query, setQuery] = useState('')
 
   return (
-    <div className={cn('flex min-h-0 flex-col gap-2 overflow-x-hidden', embedded ? 'flex-1' : 'panel overflow-y-auto p-3.5')}>
+    <div className="flex min-h-0 flex-1 flex-col gap-2 overflow-x-hidden">
       {!focused ? (
         <>
-          {!embedded && <h6 className="mx-1 mb-1.5 mt-1">Toolkit</h6>}
           {OBJECT_KINDS.map((k) => {
             const armed = armedKind === k.kind
             return (