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, 51 insertions, 0 deletions

diff --git a/tests/test-modeline-config-flycheck-render.el b/tests/test-modeline-config-flycheck-render.el
new file mode 100644
index 00000000..46d0cdef
--- /dev/null
+++ b/tests/test-modeline-config-flycheck-render.el
@@ -0,0 +1,51 @@
+;;; test-modeline-config-flycheck-render.el --- flycheck counts rendering -*- lexical-binding: t; -*-
+
+;;; Commentary:
+;; Tests for `cj/--modeline-flycheck-render', the pure formatter that
+;; turns a flycheck counts alist ((error . N) (warning . M) ...) into a
+;; propertized modeline string.  Errors carry the error face, warnings
+;; the warning face; zero-count severities are omitted; an all-clean
+;; alist (or nil) renders nothing.  Glyphs come from nerd-icons when
+;; available (private-use codepoints, safe from emojify) with plain-text
+;; fallbacks in batch mode.
+
+;;; Code:
+
+(require 'ert)
+
+(add-to-list 'load-path (expand-file-name "modules" user-emacs-directory))
+
+(require 'modeline-config)
+
+(ert-deftest test-modeline-config-flycheck-render-errors-and-warnings ()
+  "Normal: both counts render, error face on errors, warning on warnings."
+  (let ((s (cj/--modeline-flycheck-render '((error . 2) (warning . 5)))))
+    (should (stringp s))
+    (should (string-match-p "2" s))
+    (should (string-match-p "5" s))
+    (let ((epos (string-match "2" s))
+          (wpos (string-match "5" s)))
+      (should (eq (get-text-property epos 'face s) 'error))
+      (should (eq (get-text-property wpos 'face s) 'warning)))))
+
+(ert-deftest test-modeline-config-flycheck-render-errors-only ()
+  "Normal: warnings absent when their count is zero or missing."
+  (let ((s (cj/--modeline-flycheck-render '((error . 3)))))
+    (should (stringp s))
+    (should (string-match-p "3" s))
+    (should-not (text-property-any 0 (length s) 'face 'warning s))))
+
+(ert-deftest test-modeline-config-flycheck-render-clean-nil ()
+  "Boundary: zero counts render nothing."
+  (should-not (cj/--modeline-flycheck-render '((error . 0) (warning . 0)))))
+
+(ert-deftest test-modeline-config-flycheck-render-nil-input ()
+  "Boundary: nil counts alist renders nothing."
+  (should-not (cj/--modeline-flycheck-render nil)))
+
+(ert-deftest test-modeline-config-flycheck-render-info-ignored ()
+  "Boundary: info-level counts alone render nothing (errors/warnings only)."
+  (should-not (cj/--modeline-flycheck-render '((info . 4)))))
+
+(provide 'test-modeline-config-flycheck-render)
+;;; test-modeline-config-flycheck-render.el ends here