feat(modeline): mode icons, status segments, and a repair command

I rebuilt the custom modeline as pure segment helpers with thin :eval wiring:

- The nerd-icons mode icon replaces the mode-name text (cached per buffer, plain name on terminal frames), with the full mode name in the help-echo.
- New left-side segments: modified dot / read-only lock (file buffers only), remote @host tag, Narrow tag that widens on click, point-based percentage, region selection info, and a MACRO tag while a keyboard macro records.
- New right-side segments: mode-line-process (eat and compilation state was invisible) and flycheck per-severity counts with click-through to the error list, replacing the stock status text. Glyphs are nerd-icons private-use codepoints so emojify can't rewrite them, with text fallbacks when icons are unavailable.
- cj/modeline-reset kills a hijacked buffer-local mode-line-format (two-column mode, ediff, calc).
- Optional taller bar via cj/modeline-height-factor, a display height property on the padding space so the theme's mode-line faces stay untouched.
- Housekeeping: the dead user-constants require and stale commentary are gone, cj/modeline-vc-faces left the risky-local-variable list, and the cache-key defun is cj/--modeline-vc-cache-key so it no longer shadows the same-named defvar.

Percent signs from :eval strings go through the mode-line %-construct pass, so the position segment emits %% for a literal percent.

1 files changed, 73 insertions, 0 deletions

diff --git a/tests/test-modeline-config-buffer-status.el b/tests/test-modeline-config-buffer-status.el
new file mode 100644
index 00000000..123f1062
--- /dev/null
+++ b/tests/test-modeline-config-buffer-status.el
@@ -0,0 +1,73 @@
+;;; test-modeline-config-buffer-status.el --- buffer-status segment -*- lexical-binding: t; -*-
+
+;;; Commentary:
+;; Tests for `cj/--modeline-buffer-status': the modified / read-only
+;; indicator.  Read-only wins over modified; the modified dot shows only
+;; for file-visiting buffers (special buffers are perpetually modified
+;; and would be noise); clean file buffers show nothing.
+
+;;; Code:
+
+(require 'ert)
+
+(add-to-list 'load-path (expand-file-name "modules" user-emacs-directory))
+
+(require 'modeline-config)
+
+(ert-deftest test-modeline-config-buffer-status-modified-file-shows-dot ()
+  "Normal: a modified file-visiting buffer returns the warning-faced dot."
+  (let ((file (make-temp-file "modeline-status-" nil ".txt")))
+    (unwind-protect
+        (with-current-buffer (find-file-noselect file)
+          (insert "x")
+          (let ((status (cj/--modeline-buffer-status)))
+            (should (stringp status))
+            (should (string-match-p "●" status))
+            (should (eq (get-text-property
+                         (string-match "●" status) 'face status)
+                        'warning)))
+          (set-buffer-modified-p nil)
+          (kill-buffer))
+      (delete-file file))))
+
+(ert-deftest test-modeline-config-buffer-status-clean-file-nil ()
+  "Normal: an unmodified file-visiting buffer returns nil."
+  (let ((file (make-temp-file "modeline-status-" nil ".txt")))
+    (unwind-protect
+        (with-current-buffer (find-file-noselect file)
+          (should-not (cj/--modeline-buffer-status))
+          (kill-buffer))
+      (delete-file file))))
+
+(ert-deftest test-modeline-config-buffer-status-read-only-shows-lock ()
+  "Normal: a read-only buffer returns the read-only indicator."
+  (with-temp-buffer
+    (setq buffer-read-only t)
+    (let ((status (cj/--modeline-buffer-status)))
+      (should (stringp status))
+      (should (> (length status) 0)))))
+
+(ert-deftest test-modeline-config-buffer-status-read-only-wins-over-modified ()
+  "Boundary: read-only + modified shows the read-only indicator, not the dot."
+  (let ((file (make-temp-file "modeline-status-" nil ".txt")))
+    (unwind-protect
+        (with-current-buffer (find-file-noselect file)
+          (insert "x")
+          (setq buffer-read-only t)
+          (let ((status (cj/--modeline-buffer-status)))
+            (should (stringp status))
+            (should-not (string-match-p "●" status)))
+          (setq buffer-read-only nil)
+          (set-buffer-modified-p nil)
+          (kill-buffer))
+      (delete-file file))))
+
+(ert-deftest test-modeline-config-buffer-status-modified-non-file-nil ()
+  "Boundary: a modified non-file buffer (scratch-like) returns nil."
+  (with-temp-buffer
+    (insert "x")
+    (should (buffer-modified-p))
+    (should-not (cj/--modeline-buffer-status))))
+
+(provide 'test-modeline-config-buffer-status)
+;;; test-modeline-config-buffer-status.el ends here