fix: Widget and detail page graphical improvements

[rubenvdlinde]

Problem

• KPI cards render as cards-in-cards (double border) on dashboards
• Widget content not full-width (My Work, Client Overview)
• Detail page sidebar renders inline instead of as proper NcAppSidebar
• CnStatsBlock overflows narrow grid cells

Changes

• CnWidgetWrapper: Add borderless and flush props
• CnDetailCard: Add flush prop for edge-to-edge tables
• CnStatsBlock: Responsive sizing with width: 100%, text truncation
• CnDashboardPage: Auto-set borderless when showTitle=false, pass flush from layout
• CnDashboardGrid: Transparent background for borderless widgets
• CnDetailPage: External sidebar via objectSidebarState inject pattern
• CnObjectSidebar: Add proper subtitle prop
• rollup.config.js: Fix apexcharts build (resolve .min without extension)