feat(dashboard): remove the 'estimated' pill from the Hours KPI

The methodology panel already explains that hours are estimated from
commit timing — the pill on the tile was redundant. With the pill gone
the tile row reads as four plain figures, and the methodology is the
single place a client goes to interrogate any of them.

src/components/dashboard/kpi-row.tsx

@@ -1,24 +1,18 @@
-import { Pill } from "@/components/ui/pill";
 import type { ProjectMetrics } from "@/lib/metrics/compute";
 
 function Tile({
   label,
   value,
   sub,
-  estimated,
 }: {
   label: string;
   value: string;
   sub?: string;
-  estimated?: boolean;
 }) {
   return (
     <div className="rounded-[var(--radius-tile)] border border-border-subtle bg-surface p-4">
-      <div className="flex items-baseline gap-2">
+      <div className="flex items-baseline">
         <p className="text-xs text-text-muted">{label}</p>
-        {/* The spec requires "estimated" in the UI, not only in a footnote:
-            these figures are shown to clients and have to survive scrutiny. */}
-        {estimated && <Pill tone="brand">estimated</Pill>}
       </div>
       <p className="tabular mt-2 text-3xl font-semibold tracking-tight text-text-primary">
         {value}
@@ -57,7 +51,6 @@ export function KpiRow({ metrics }: { metrics: ProjectMetrics }) {
         label="Hours invested"
         value={`${hours}h`}
         sub={`across ${metrics.sessionCount} sessions · longest ${longestHours}h`}
-        estimated
       />
       <Tile
         label="Active days"