gptel-rewrite: Make other modes not clobber rewrite overlay (#744)

When rewriting sections of Lisp or other code where the initial
character is a parenthesis, it results in `show-paren-mode'
highlighting the entire overlay when the point is positioned within
the overlay area.  Other modes like `hl-line-mode' cause similar
issues.  Avoid this by using a very high priority for
`gptel-rewrite-highlight-face'.  (#691)

* gptel-rewrite.el (gptel-rewrite-highlight-face): Inherit from the
`default' face to avoid foreground being the same as
`show-paren-match', which is usually a reverse color.
(gptel--rewrite-callback): Use priority 2000.

Author: pabl0

gptel-rewrite.el

@@ -87,9 +87,9 @@ overlay."
 
 (defface gptel-rewrite-highlight-face
   '((((class color) (min-colors 88) (background dark))
-     :background "#041714" :extend t)
+     :background "#041714" :extend t :inherit default)
     (((class color) (min-colors 88) (background light))
-     :background "light goldenrod yellow" :extend t)
+     :background "light goldenrod yellow" :extend t :inherit default)
     (t :inherit secondary-selection))
   "Face for highlighting regions with pending rewrites."
   :group 'gptel)
@@ -434,6 +434,7 @@ INFO is the async communication channel for the rewrite request."
               (add-hook 'eldoc-documentation-functions #'gptel--rewrite-key-help nil 'local)
               ;; (overlay-put ov 'gptel-rewrite response)
               (overlay-put ov 'face 'gptel-rewrite-highlight-face)
+	      (overlay-put ov 'priority 2000)
               (overlay-put ov 'keymap gptel-rewrite-actions-map)
               (overlay-put ov 'mouse-face 'highlight)
               (overlay-put