feat(keys): role-based gateway keys with admin management UI and per-user model scope

internal/config/config.go

@@ -121,4 +121,17 @@ func (c *Config) ApplyDefaults() error {
 // RuntimeConfig is the persisted web-UI editable slice (sources added/edited).
 type RuntimeConfig struct {
 	Sources []Source `json:"sources"`
+	Keys    []GWKey  `json:"keys,omitempty"`
+}
+
+// GWKey is a gateway API key persisted in the runtime store. Role is "admin"
+// (full management) or "user" (sees only its own key); Models is the allowed
+// model whitelist (nil/empty = all models).
+type GWKey struct {
+	Key       string   `json:"key"`
+	Role      string   `json:"role"`
+	Name      string   `json:"name,omitempty"`
+	Models    []string `json:"models,omitempty"`
+	Note      string   `json:"note,omitempty"`
+	CreatedAt int64    `json:"created_at,omitempty"`
 }