feat(dashboards): one Sim-built dashboard per workspace

A workspace now has a single dashboard that Sim builds. The Dashboards page
renders it directly, or an empty state until the first save. Folders, the
list, create, rename and move are removed; the agent reads and saves it with
dashboards get / set, and replacing existing content needs its revision. A
partial unique index enforces one live dashboard per workspace, and generic
file writes can no longer produce the dashboard content type.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01S6aTRnkiu7PxYZPNPXYEMV

Author: TheodoreSpeaks

apps/sim/app/api/workspaces/[id]/dashboard/route.ts

@@ -0,0 +1,35 @@
+import {
+  deleteWorkspaceDashboardContract,
+  readWorkspaceDashboardContract,
+} from '@/lib/api/contracts/dashboards'
+import {
+  defineInternalJsonRoute,
+  internalOrchestrationErrorPolicy,
+  internalRateLimits,
+  internalSessionAuth,
+} from '@/lib/api/server/routes'
+import {
+  deleteWorkspaceDashboard,
+  readWorkspaceDashboard,
+} from '@/lib/dashboards/application/dashboards'
+import { dashboardOperations } from '@/lib/dashboards/application/operations'
+
+export const GET = defineInternalJsonRoute({
+  contract: readWorkspaceDashboardContract,
+  auth: internalSessionAuth,
+  operation: dashboardOperations.read,
+  rateLimit: internalRateLimits.user({ bucketName: 'dashboards' }),
+  errorPolicy: internalOrchestrationErrorPolicy,
+  mapInput: ({ params }) => ({ workspaceId: params.id }),
+  useCase: readWorkspaceDashboard,
+})
+
+export const DELETE = defineInternalJsonRoute({
+  contract: deleteWorkspaceDashboardContract,
+  auth: internalSessionAuth,
+  operation: dashboardOperations.delete,
+  rateLimit: internalRateLimits.user({ bucketName: 'dashboards' }),
+  errorPolicy: internalOrchestrationErrorPolicy,
+  mapInput: ({ params }) => ({ workspaceId: params.id }),
+  useCase: deleteWorkspaceDashboard,
+})

apps/sim/app/api/workspaces/[id]/dashboards/[dashboardId]/route.ts

@@ -1,5 +1,5 @@
 import type { ComponentType } from 'react'
-import { ChartColumn, Database, File as FileIcon, Table as TableIcon } from '@sim/emcn/icons'
+import { Database, File as FileIcon, Table as TableIcon } from '@sim/emcn/icons'
 import type { FolderResourceType } from '@/lib/api/contracts/folders'
 import { folderListHref } from '@/app/workspace/[workspaceId]/components/folders/search-params'
 
@@ -10,7 +10,7 @@ import { folderListHref } from '@/app/workspace/[workspaceId]/components/folders
  */
 export type FolderedHeaderResourceType = Extract<
   FolderResourceType,
-  'file' | 'knowledge_base' | 'table' | 'dashboard'
+  'file' | 'knowledge_base' | 'table'
 >
 
 export interface FolderedResourceHeaderMeta {
@@ -36,7 +36,6 @@ export const FOLDERED_RESOURCE_HEADERS: Record<
   file: { rootLabel: 'Files', rootIcon: FileIcon, listSegment: 'files' },
   knowledge_base: { rootLabel: 'Knowledge bases', rootIcon: Database, listSegment: 'knowledge' },
   table: { rootLabel: 'Tables', rootIcon: TableIcon, listSegment: 'tables' },
-  dashboard: { rootLabel: 'Dashboards', rootIcon: ChartColumn, listSegment: 'dashboards' },
 }
 
 /**