test: add 86 new tests, fix 3 production bugs, fix 8 stale tests

New test coverage (86 tests across 7 files):
- custom-case: 43 tests (title-case-region, upcase-dwim, downcase-dwim)
- custom-datetime: 10 tests (all insert methods with mocked time)
- config-utilities: 11 tests (format-build-time type branching)
- org-capture-config: 22 tests (date-prefix + event-content)

Production bugs found and fixed:
- custom-case: title-case-region crashes on whitespace/punctuation-only input
  (char-after returns nil when no word chars found)
- org-capture-config: browser branch missing empty-string guard on :initial
  plist value, producing stray newline in capture output
- mousetrap-mode: keymap never registered in minor-mode-map-alist, so mode
  was silently not blocking any mouse events. Now pushes/removes on toggle.

Additional fixes:
- local-repository: fix cons cell syntax bug in localrepo-initialize
  (was calling vars as functions instead of using cons)
- dupre-theme tests: update rainbow-delimiter color expectations
- mousetrap tests: update dashboard profile (primary-click → scroll+primary)
- music completion test: bind completion-ignore-case to prevent pollution
- Delete redundant interactive recording test (duplicate of ERT version)

Refactoring:
- org-capture-config: extract cj/org-capture--date-prefix pure function
  from cj/org-capture-format-event-headline for testability

Test checklist: todo.org updated to [11/25], removed untestable modules

1 files changed, 89 insertions, 0 deletions

diff --git a/tests/test-org-capture-config-event-content.el b/tests/test-org-capture-config-event-content.el
new file mode 100644
index 00000000..d32b9ef8
--- /dev/null
+++ b/tests/test-org-capture-config-event-content.el
@@ -0,0 +1,89 @@
+;;; test-org-capture-config-event-content.el --- Tests for cj/org-capture-event-content -*- lexical-binding: t; -*-
+
+;;; Commentary:
+;; Tests for the cj/org-capture-event-content function from org-capture-config.el.
+;;
+;; Returns selected text for event capture, prioritizing:
+;; 1. org-store-link-plist :initial (from browser via org-protocol)
+;; 2. org-capture-plist :initial (from Emacs region)
+;; 3. Empty string (no selection)
+;;
+;; Note: org-capture-plist is defined by org-capture at runtime. We ensure
+;; it's declared before tests so let-binding works in batch mode.
+
+;;; Code:
+
+(require 'ert)
+(require 'org)
+
+(add-to-list 'load-path (expand-file-name "modules" user-emacs-directory))
+(require 'org-capture-config)
+
+;; Ensure org-capture-plist is declared (normally defined by org-capture at runtime)
+(defvar org-capture-plist nil)
+
+;;; Normal Cases
+
+(ert-deftest test-org-capture-config-event-content-normal-browser-selection ()
+  "Browser selection via org-protocol should be returned with leading newline."
+  (let ((org-store-link-plist '(:initial "selected from browser"))
+        (org-capture-plist '(:initial "")))
+    (should (equal (cj/org-capture-event-content)
+                   "\nselected from browser"))))
+
+(ert-deftest test-org-capture-config-event-content-normal-emacs-region ()
+  "Emacs region selection should be returned with leading newline."
+  (let ((org-store-link-plist nil)
+        (org-capture-plist '(:initial "selected in emacs")))
+    (should (equal (cj/org-capture-event-content)
+                   "\nselected in emacs"))))
+
+(ert-deftest test-org-capture-config-event-content-normal-no-selection ()
+  "No selection in either plist should return empty string."
+  (let ((org-store-link-plist nil)
+        (org-capture-plist '(:initial "")))
+    (should (equal (cj/org-capture-event-content) ""))))
+
+(ert-deftest test-org-capture-config-event-content-normal-browser-takes-priority ()
+  "Browser selection should take priority over Emacs region."
+  (let ((org-store-link-plist '(:initial "from browser"))
+        (org-capture-plist '(:initial "from emacs")))
+    (should (equal (cj/org-capture-event-content)
+                   "\nfrom browser"))))
+
+;;; Boundary Cases
+
+(ert-deftest test-org-capture-config-event-content-boundary-store-link-no-initial ()
+  "org-store-link-plist without :initial should fall through to capture plist."
+  (let ((org-store-link-plist '(:url "http://example.com"))
+        (org-capture-plist '(:initial "from emacs")))
+    (should (equal (cj/org-capture-event-content)
+                   "\nfrom emacs"))))
+
+(ert-deftest test-org-capture-config-event-content-boundary-store-link-empty-initial ()
+  "org-store-link-plist with empty :initial should fall through, not produce stray newline."
+  (let ((org-store-link-plist '(:initial ""))
+        (org-capture-plist '(:initial "")))
+    (should (equal (cj/org-capture-event-content) ""))))
+
+(ert-deftest test-org-capture-config-event-content-boundary-capture-plist-nil-initial ()
+  "Nil :initial in capture plist should return empty string."
+  (let ((org-store-link-plist nil)
+        (org-capture-plist '(:initial nil)))
+    (should (equal (cj/org-capture-event-content) ""))))
+
+(ert-deftest test-org-capture-config-event-content-boundary-multiline-selection ()
+  "Multi-line selection should be preserved."
+  (let ((org-store-link-plist nil)
+        (org-capture-plist '(:initial "line one\nline two\nline three")))
+    (should (equal (cj/org-capture-event-content)
+                   "\nline one\nline two\nline three"))))
+
+(ert-deftest test-org-capture-config-event-content-boundary-both-plists-nil ()
+  "Both plists nil should return empty string."
+  (let ((org-store-link-plist nil)
+        (org-capture-plist nil))
+    (should (equal (cj/org-capture-event-content) ""))))
+
+(provide 'test-org-capture-config-event-content)
+;;; test-org-capture-config-event-content.el ends here