feat(pdf+org-latex): pdf-tools config + fix tabularx via default-table-environment

org-latex tabularx:
  - Dropped advice/filter/hook approaches (all caused issues)
  - Use org-latex-default-table-environment="tabularx" — org natively
    handles tabularx/tabulary by inserting \linewidth width arg automatically
  - tabularx added to org-latex-packages-alist

pdf-tools:
  - pdf-tools-install :no-query (auto-builds server binary)
  - pdf-view: fit-page default, Retina scaling, midnight dark theme,
    continuous scrolling, auto-revert after LaTeX re-export, no line numbers
  - Evil keybinds: j/k scroll, J/K pages, gg/G first/last, +/-/= zoom,
    W fit-width, / search, m midnight toggle, a annotate, q quit
  - org-file-apps on macOS: PDF opens in Emacs (pdf-view-mode via auto-mode)
    instead of system Preview

config.el

@@ -325,42 +325,17 @@ Bound to cmd+v in org-mode and markdown-mode."
 ;;; ORG MODE — LATEX EXPORT
 ;;; ============================================================
 
-;; LaTeX table export: replace tabular → tabularx{\textwidth}
-;; Around advice on org-latex-table (more reliable than filter hooks).
-;; No buffer modification → no recursion risk.
-(defun my/org-latex-table-tabularx (orig-fn table contents info)
-  "Wrap org-latex-table output: replace tabular with tabularx{\\textwidth}."
-  (let ((result (funcall orig-fn table contents info)))
-    (when (stringp result)
-      (setq result
-            (replace-regexp-in-string
-             "\\\\begin{tabular}{\\([^}]*\\)}"
-             "\\\\begin{tabularx}{\\\\textwidth}{\\1}"
-             result))
-      (setq result
-            (replace-regexp-in-string
-             "\\\\end{tabular}"
-             "\\\\end{tabularx}"
-             result)))
-    result))
-
-(with-eval-after-load 'ox-latex
-  (advice-add 'org-latex-table :around #'my/org-latex-table-tabularx)
+;; LaTeX table export: use tabularx as default environment.
+;; Org natively supports tabularx: when environment is "tabularx" or "tabulary",
+;; it automatically inserts the required width argument (\linewidth).
+;; No buffer modification, no advice, no filter needed.
+(after! ox-latex
+  (setq org-latex-default-table-environment "tabularx")
   (add-to-list 'org-latex-packages-alist '("" "tabularx")))
 
 ;; Optional: enable booktabs style (horizontal rules in tables)
 ;; (setq org-latex-tables-booktabs t)
 
-;; macOS: open exported PDF with system 'open' (async → no beachball)
-;; Without this, org-open-file may call open synchronously or fail silently.
-(when (eq system-type 'darwin)
-  (setq org-file-apps
-        '((auto-mode  . emacs)
-          (directory  . emacs)
-          ("\\.mm\\'" . default)
-          ("\\.x?html?\\'" . default)
-          ("\\.pdf\\'" . "open %s"))))
-
 ;; Ensure latexmk doesn't hang on errors (nonstopmode + force-continue)
 ;; Doom latex module usually sets this, but belt+suspenders for macOS.
 (after! org
@@ -1028,3 +1003,57 @@ Otherwise: runs interactive ement-connect, then opens rooms after sync."
        :desc "Join room"            "j" #'ement-join-room
        :desc "Notifications"        "n" #'ement-notifications
        :desc "Mentions"             "m" #'ement-mentions))
+
+
+;;; ============================================================
+;;; PDF TOOLS
+;;; ============================================================
+
+;; pdf-tools: install server binary on first load
+(after! pdf-tools
+  (pdf-tools-install :no-query))
+
+;; pdf-view-mode settings
+(after! pdf-view
+  ;; Fit page to window width by default
+  (setq-default pdf-view-display-size 'fit-page)
+  ;; High-res rendering on Retina displays
+  (setq pdf-view-use-scaling t
+        pdf-view-use-imagemagick nil)
+  ;; Midnight mode (dark background) — toggle with M-m or keybind
+  (setq pdf-view-midnight-colors '("#d4d4d4" . "#1c1c1c"))
+  ;; Continuous scrolling across pages
+  (setq pdf-view-continuous t)
+  ;; No line-number gutter
+  (add-hook 'pdf-view-mode-hook #'(lambda ()
+    (display-line-numbers-mode -1)))
+  ;; Auto-revert when PDF is regenerated (e.g. after org LaTeX export)
+  (add-hook 'pdf-view-mode-hook #'auto-revert-mode))
+
+;; Evil-friendly keybinds in pdf-view
+(after! pdf-view
+  (evil-define-key 'normal pdf-view-mode-map
+    "j"  #'pdf-view-next-line-or-next-page
+    "k"  #'pdf-view-previous-line-or-previous-page
+    "J"  #'pdf-view-next-page
+    "K"  #'pdf-view-previous-page
+    "gg" #'pdf-view-first-page
+    "G"  #'pdf-view-last-page
+    "+"  #'pdf-view-enlarge
+    "-"  #'pdf-view-shrink
+    "="  #'pdf-view-fit-page-to-window
+    "W"  #'pdf-view-fit-width-to-window
+    "/"  #'isearch-forward
+    "?"  #'isearch-backward
+    "m"  #'pdf-view-midnight-minor-mode
+    "a"  #'pdf-annot-add-highlight-markup-annotation
+    "q"  #'quit-window))
+
+;; Open PDFs from org export in Emacs (pdf-view-mode) instead of Preview
+(when (eq system-type 'darwin)
+  (setq org-file-apps
+        '((auto-mode  . emacs)
+          (directory  . emacs)
+          ("\\.mm\\'" . default)
+          ("\\.x?html?\\'" . default)
+          ("\\.pdf\\'" . emacs))))   ; find-file → pdf-view-mode via auto-mode-alist