feat(telega-config): guard launcher with a helpful message when telega is missing

Without the guard, both `C-; G' and the dashboard Telegram icon
trigger telega's autoload stub directly.  When the package isn't
installed yet the user sees `Cannot open load file: telega' in
`*Messages*' with no hint about what to do.

Wrap the launcher in `cj/telega' that checks `featurep' /
`locate-library' first.  If telega is present, delegate to it.
Otherwise signal a `user-error' pointing at `scripts/setup-telega.sh'
and the manual `M-x package-install RET telega' fallback.  Rebind
`C-; G' and the dashboard "g" key + Telegram icon callback to the
wrapper.

Two new tests in `test-telega-config.el' cover the wrapper paths
(absent -> user-error with the recovery hint; present -> delegates
to `telega') alongside the updated binding assertion.

1 files changed, 27 insertions, 2 deletions

diff --git a/tests/test-telega-config.el b/tests/test-telega-config.el
index ace96555..c642d1f6 100644
--- a/tests/test-telega-config.el
+++ b/tests/test-telega-config.el
@@ -18,8 +18,33 @@
   (should (featurep 'telega-config)))
 
 (ert-deftest test-telega-config-launcher-binding-is-telega ()
-  "Normal: =C-; G= invokes `telega'."
-  (should (eq (keymap-lookup cj/custom-keymap "G") #'telega)))
+  "Normal: =C-; G= invokes the launcher wrapper, which routes to
+`telega' when installed or signals a helpful user-error otherwise."
+  (should (eq (keymap-lookup cj/custom-keymap "G") #'cj/telega)))
+
+(ert-deftest test-telega-config-launcher-without-package-signals-user-error ()
+  "Error: with telega absent, the launcher signals a `user-error' that
+mentions the recovery path instead of falling through to the autoload
+stub's cryptic load-file failure."
+  (cl-letf (((symbol-function 'featurep)
+             (lambda (sym &optional _sub)
+               (and (not (eq sym 'telega)) t)))
+            ((symbol-function 'locate-library)
+             (lambda (lib &rest _) (unless (equal lib "telega") t))))
+    (let* ((err (should-error (cj/telega) :type 'user-error))
+           (msg (error-message-string err)))
+      (should (string-match-p "telega not installed" msg))
+      (should (string-match-p "setup-telega\\.sh\\|package-install" msg)))))
+
+(ert-deftest test-telega-config-launcher-with-package-calls-telega ()
+  "Normal: with telega loadable, the launcher delegates to `telega'."
+  (let (called)
+    (cl-letf (((symbol-function 'featurep)
+               (lambda (sym &optional _sub) (eq sym 'telega)))
+              ((symbol-function 'telega)
+               (lambda (&rest _) (setq called t))))
+      (cj/telega))
+    (should called)))
 
 (provide 'test-telega-config)
 ;;; test-telega-config.el ends here