Phase 4: first-run onboarding + TUI config panel improvements

- Add providers-configured-p function (daemon-side detection)
- Add welcome log messages when no LLM providers configured
- Rewrite config panel with 4 interactive sections (Providers, Cascade, Models, View)
- Add first-run welcome messages in TUI chat on connect
- Fix config-render-models paren balance

lisp/core-skills.lisp

@@ -219,8 +219,8 @@
                       (incf exported)
                       (let ((existing (find-symbol (symbol-name sym) target-pkg)))
                         (when existing (unintern existing target-pkg)))
-                       (import sym target-pkg)
-                       (ignore-errors (export sym target-pkg))))
+                      (import sym target-pkg)
+                      (export sym target-pkg)))
                   (log-message "LOADER: Exported ~a symbols from ~a to :PASSEPARTOUT"
                                exported (package-name (find-package pkg-name))))