refactor(design): strip color bars from org chart cards

Remove the ink-blue top rank bar, running-state border override, and
green glow shadow from org chart cards. The tree layout already
communicates rank by position, and a dashed ink-blue connection line
plus the bottom-right status dot + ping animation already mark
running agents — duplicating the signal through a card-wide color
band and a cyan/green shadow was pure decoration.

- Drop the rounded-t [4px bg-primary | 2px bg-border] top bar entirely.
- Running state stops overriding border to var(--primary); all running
  cards fall back to the neutral border-border like everyone else.
- Running state stops emitting a success-tinted glow (shadow-[0_0_12px
  color-mix(... var(--success) 15% ...)]) — kami rule 8 bans drop
  shadows, and the tint introduced an unauthorized green.
- Hover switches from shadow-lg + translate-y-0.5 to a subtle
  hover:bg-muted/30 tint.
- Active/running avatar circle switches from bg-success-muted
  text-success to bg-accent text-primary (kami's ink-blue tint),
  removing the last green chrome on the page.
- Heartbeat icon switches from text-success to text-primary.
- Avatar initials move from font-bold (700) to font-semibold (600).

Error / pending_approval keep their destructive border (red), since
kami reserves the warm terra red for genuine error/destructive state
per design.md color system.

Typecheck and build:verify clean.

src/renderer/components/organization/OrgChart.tsx

@@ -158,7 +158,7 @@ export function OrgChart({ agents, connectors, onSelectAgent }: { agents: AgentR
                   <span className="mt-0.5 text-[11px] leading-tight text-muted-foreground">{node.agent.title || node.agent.role}</span>
                   <div className="mt-1.5 flex items-center gap-2">
                     <span className="rounded bg-muted px-1.5 py-0.5 text-[11px] font-semibold tracking-tight text-muted-foreground">{connectorLabel}</span>
-                    {node.agent.heartbeatEnabled ? <Heartbeat size={10} className="text-success" /> : null}
+                    {node.agent.heartbeatEnabled ? <Heartbeat size={10} className="text-primary" /> : null}
                   </div>
                 </div>
               </div>