feat: add AI Gateway coderd key CRUD endpoints (#25565)

Adds create, list and delete endpoints for AI Gateway keys.
Those keys are used to authenticate into Coderd.
All endpoints require Owner permission.

enterprise/coderd/coderd.go

@@ -298,6 +298,18 @@ func New(ctx context.Context, options *Options) (_ *API, err error) {
 		r.Route("/aibridge/proxy", aibridgeproxyHandler(api, apiKeyMiddleware))
 	})
 
+	api.AGPL.APIHandler.Group(func(r chi.Router) {
+		r.Route("/aibridge/keys", func(r chi.Router) {
+			r.Use(
+				apiKeyMiddleware,
+				api.RequireFeatureMW(codersdk.FeatureAIBridge),
+			)
+			r.Get("/", api.aiGatewayKeys)
+			r.Post("/", api.postAIGatewayKey)
+			r.Delete("/{key}", api.deleteAIGatewayKey)
+		})
+	})
+
 	api.AGPL.APIHandler.Group(func(r chi.Router) {
 		r.Get("/entitlements", api.serveEntitlements)
 		// /regions overrides the AGPL /regions endpoint