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, 37 insertions, 0 deletions

diff --git a/tests/test-modeline-config-reset.el b/tests/test-modeline-config-reset.el
new file mode 100644
index 00000000..54b7bb2f
--- /dev/null
+++ b/tests/test-modeline-config-reset.el
@@ -0,0 +1,37 @@
+;;; test-modeline-config-reset.el --- cj/modeline-reset -*- lexical-binding: t; -*-
+
+;;; Commentary:
+;; Tests for `cj/modeline-reset', the repair command for buffers whose
+;; `mode-line-format' was hijacked buffer-locally (two-column mode, ediff,
+;; calc).  It kills the buffer-local value so the default format returns.
+
+;;; Code:
+
+(require 'ert)
+
+(add-to-list 'load-path (expand-file-name "modules" user-emacs-directory))
+
+(require 'modeline-config)
+
+(ert-deftest test-modeline-config-reset-kills-local-format ()
+  "Normal: a hijacked buffer-local mode-line-format is removed."
+  (with-temp-buffer
+    (setq-local mode-line-format '("hijacked"))
+    (should (local-variable-p 'mode-line-format))
+    (cj/modeline-reset)
+    (should-not (local-variable-p 'mode-line-format))
+    (should (eq mode-line-format (default-value 'mode-line-format)))))
+
+(ert-deftest test-modeline-config-reset-noop-without-local ()
+  "Boundary: harmless when the buffer has no local mode-line-format."
+  (with-temp-buffer
+    (should-not (local-variable-p 'mode-line-format))
+    (cj/modeline-reset)
+    (should-not (local-variable-p 'mode-line-format))))
+
+(ert-deftest test-modeline-config-reset-is-a-command ()
+  "Normal: cj/modeline-reset is interactive."
+  (should (commandp #'cj/modeline-reset)))
+
+(provide 'test-modeline-config-reset)
+;;; test-modeline-config-reset.el ends here