wip: context-meter + model-label UI and provider/inference tweaks

Checkpoint of in-flight work so the orchestrator branch can rebase onto a
clean main: ContextBar → ContextMeter, model-label helper, model/agent picker
+ provider-snapshot/registry changes, inference payload + message-columns.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apps/web/src/components/ModelPicker.tsx

@@ -10,6 +10,7 @@ import {
 } from '@/components/ui/dropdown-menu';
 import { BottomSheet } from '@/components/BottomSheet';
 import { useViewport } from '@/hooks/useViewport';
+import { formatModelLabel } from '@/lib/model-label';
 
 interface Props {
   value: string;
@@ -45,7 +46,7 @@ function ModelList({
           className="w-full text-left flex items-center gap-2 font-mono text-xs px-2 py-1.5 hover:bg-accent rounded"
         >
           <Check className={`size-3 ${m.id === value ? 'opacity-100' : 'opacity-0'}`} />
-          <span className="truncate">{m.id}</span>
+          <span className="truncate">{formatModelLabel(m.id)}</span>
         </button>
       ))}
     </>
@@ -83,7 +84,7 @@ export function ModelPicker({ value, onChange }: Props) {
           onClick={() => setOpen(true)}
           aria-label={`Model: ${value}`}
           title={value}
-          className="inline-flex items-center justify-center min-h-[44px] min-w-[44px] rounded text-muted-foreground hover:text-foreground"
+          className="inline-flex items-center justify-center min-h-[36px] min-w-[44px] rounded text-muted-foreground hover:text-foreground"
         >
           <Cpu className="size-4" />
         </button>
@@ -103,7 +104,7 @@ export function ModelPicker({ value, onChange }: Props) {
           type="button"
           className="text-xs font-mono text-muted-foreground hover:text-foreground flex items-center gap-1 px-1.5 py-0.5 rounded hover:bg-muted/60"
         >
-          {value}
+          {formatModelLabel(value)}
           <ChevronDown className="size-3 opacity-70" />
         </button>
       </DropdownMenuTrigger>
@@ -123,7 +124,7 @@ export function ModelPicker({ value, onChange }: Props) {
             <Check
               className={`size-3 ${m.id === value ? 'opacity-100' : 'opacity-0'}`}
             />
-            {m.id}
+            {formatModelLabel(m.id)}
           </DropdownMenuItem>
         ))}
       </DropdownMenuContent>