fix(dashboard): clear the two ghe-copilot typecheck regressions from #7546

AgentEmoji's AGENT_COLORS is a Record<AgentId, …>; #7546 widened AgentId with
'ghe-copilot' without adding the entry (TS2741). GheConfigStep typed its error
prop as `unknown` and rendered it directly, which is not a ReactNode (TS2322).

Both are counted by check:dashboard-typecheck, which was failing on the pure
release tip (261 live vs 259 frozen) and reddening Fast Quality Gates for every
open PR. Now back to the frozen 259.

changelog.d/maintenance/ghe-copilot-registry-mirrors.md

@@ -1 +1,2 @@
 - fix(oauth): register `ghe-copilot` in the OAuth provider id map and the client-safe MITM host mirror, which #7546 left out of both — the gap turned the whole release branch red on `oauth-providers-config` and `mitm-tool-hosts`
+- fix(dashboard): add the ghe-copilot entry to the traffic-inspector agent map and type `GheConfigStep`'s `error` prop as a renderable string, clearing the two dashboard-typecheck regressions #7546 left behind

src/app/(dashboard)/dashboard/tools/traffic-inspector/components/shared/AgentEmoji.tsx

@@ -6,6 +6,7 @@ const AGENT_COLORS: Record<AgentId, { emoji: string; label: string; color: strin
   antigravity: { emoji: "🔵", label: "AG", color: "text-blue-400" },
   kiro: { emoji: "🟠", label: "KR", color: "text-orange-400" },
   copilot: { emoji: "🟢", label: "CP", color: "text-green-400" },
+  "ghe-copilot": { emoji: "🟩", label: "GHE", color: "text-emerald-400" },
   codex: { emoji: "🟣", label: "CD", color: "text-purple-400" },
   cursor: { emoji: "🔶", label: "CU", color: "text-yellow-400" },
   zed: { emoji: "🔷", label: "ZD", color: "text-sky-400" },

src/shared/components/oauthModal/GheConfigStep.tsx

@@ -6,7 +6,8 @@ import Input from "@/shared/components/Input";
 type GheConfigStepProps = {
   gheUrl: string;
   setGheUrl: (value: string) => void;
-  error: unknown;
+  /** Rendered inline below the form; `unknown` is not a valid ReactNode. */
+  error?: string | null;
   setError: (value: string) => void;
   startOAuthFlow: () => void;
 };