feat(config-settings): add path row event handling (Enter edit, LEFT clear, RIGHT no-op)

- Add __fish_user_dots_path as 8th entry in vars list
- Update panel_h from 14 to 16 (matches draw function's 16-line output)
- Clamp cur_row down to min(7, ...) to allow navigation to path row
- Add did_redraw flag (reset per iteration) to skip double-redraw after Enter
- Add Enter handler for row 7: erases panel, prompts for path, sets or clears
  __fish_user_dots_path universally, redraws, sets did_redraw
- Special-case RIGHT on row 7 as no-op (path is set via Enter only)
- Special-case LEFT on row 7 to clear path var via apply DEFAULT
- Add Enter key hint to --help navigation section
- Fix EXAMPLE block in __config_settings_draw docstring to include 8th arg

functions/__config_settings_draw.fish

@@ -32,7 +32,7 @@
 #       __fish_config_op_aliases __fish_config_op_autoexec \
 #       __fish_config_op_overrides __fish_config_op_integrations \
 #       __fish_config_op_logging __fish_config_op_greeting \
-#       __fish_config_opinionated
+#       __fish_config_opinionated __fish_user_dots_path
 function __config_settings_draw
     set -l cur_row   $argv[1]
     set -l cur_scope $argv[2]