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-project.el

@@ -98,7 +98,10 @@
 
 ;; Integration with consult if available
 (with-eval-after-load 'consult
-  (setq consult-project-function #'project-root))
+  (setq consult-project-function
+        (lambda (_may-prompt)
+          (when-let ((proj (project-current)))
+            (project-root proj)))))
 
 ;; Keybindings - Main project map on C-x p (built-in)
 ;; Additional compatibility bindings for muscle memory