feat(packages): Add gptel and org-habit

- Configure gptel to use the Gemini 2.5 Pro model via the GitHub Copilot backend.
- Enable the org-habit module for habit tracking in Org mode.

config.el

@@ -82,6 +82,13 @@
            (typst-ts-mode . rainbow-delimiters-mode)
            (foo-mode . rainbow-delimiters-mode)))
 
+(use-package! gptel
+    :config
+    (setq! gptel-api-key "e994f45f9b46cc8608bd2e9cd508417255514e96913b1764aab612512aa66449")
+    (setq gptel-model 'claude-sonnet-4.5)
+    (setq gptel-backend (gptel-make-gh-copilot "Copilot"))
+    )
+
 (use-package! typst-ts-mode
   :init
   (add-hook 'typst-ts-mode-hook #'eglot-ensure)
@@ -117,6 +124,8 @@
   (define-key typst-ts-mode-map (kbd "C-c C-l") #'typst-preview-mode)
   )
 
+(add-to-list 'org-modules 'org-habit)
+
 (use-package org-latex-preview
   :hook ((org-mode . org-latex-preview-mode)
          (org-latex-preview-mode . org-latex-preview-center-mode))