Improve startup performance and reduce resource usage

- Defer elfeed auto-update timers until first use (was running at startup)
- Fix consult-project-function to handle nil project gracefully
- Remove duplicate delete-trailing-whitespace hook
- Remove redundant diff-hl find-file-hook (global-diff-hl-mode handles it)
- Reduce treemacs resource usage (lower git entries, disable filewatch)
- Make dired dotfiles-first sorting opt-in (C-c s to sort, C-c S to toggle)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

lisp/init-treemacs.el

@@ -26,7 +26,7 @@
         treemacs-directory-name-transformer      #'identity
         treemacs-display-in-side-window          t
         treemacs-eldoc-display                   'simple
-        treemacs-file-event-delay                2000
+        treemacs-file-event-delay                5000  ; Increased from 2000 for less CPU usage
         treemacs-file-follow-delay                0.2
         treemacs-follow-after-init                t
         treemacs-expand-after-init               t
@@ -35,7 +35,7 @@
         treemacs-indentation                     2
         treemacs-indentation-string              " "
         treemacs-is-never-other-window           nil
-        treemacs-max-git-entries                  5000
+        treemacs-max-git-entries                  500   ; Reduced from 5000 for faster git status
         treemacs-missing-project-action          'ask
         treemacs-move-forward-on-expand          nil
         treemacs-no-delete-other-windows         t
@@ -59,7 +59,7 @@
         treemacs-workspace-switch-cleanup        nil)
 
   (treemacs-follow-mode t)
-  (treemacs-filewatch-mode t)
+  (treemacs-filewatch-mode nil)  ; Disabled by default - use M-x treemacs-filewatch-mode to enable
   (treemacs-fringe-indicator-mode 'always)
   (when treemacs-python-executable
     (treemacs-git-commit-diff-mode t))