chore: coverage, autoload fix, and internal cleanup for org-drill

A batch of test-coverage and hardening work, squashed from the test-work branch.

Tests: deduplicated a colliding leitner-capture test name so make test-name loads again. Added SM2 assert-failure cases, the six basic multicloze variant delegations, the three English-side spanish-verb branches, and org-drill-current-scope branch coverage.

Fix: the entry-point commands (org-drill itself, cram-tree, tree, directory, resume, relearn-item, strip-all-data, merge-buffers) carried no autoload cookies, so M-x failed from a fresh install until something pulled the file in. They're autoloaded now.

Perf: org-drill-shuffle was quadratic because it indexed a list with elt on every swap. It runs a linear Fisher-Yates pass over a vector now, and it checks its argument is a list.

Feat: added org-drill-version, a constant plus an interactive command, so a bug reporter doesn't have to open the file header.

Refactor: extracted org-drill--format-tense-mood, shared by the two verb-conjugation presenters that each carried a copy.

Docs: explained the SM8 magic numbers in the simple8 helpers as empirical fits rather than tunable knobs.

1 files changed, 28 insertions, 0 deletions

diff --git a/tests/test-org-drill-version.el b/tests/test-org-drill-version.el
new file mode 100644
index 0000000..4dc71d3
--- /dev/null
+++ b/tests/test-org-drill-version.el
@@ -0,0 +1,28 @@
+;;; test-org-drill-version.el --- Tests for org-drill-version  -*- lexical-binding: t; -*-
+
+;;; Commentary:
+;; org-drill-version is both a constant (the package version string) and an
+;; interactive command that reports it, so bug reporters don't have to open
+;; the file header.
+
+;;; Code:
+
+(require 'ert)
+(require 'org-drill)
+
+(ert-deftest test-org-drill-version-is-a-version-string ()
+  "The constant is a non-empty dotted version string."
+  (should (stringp org-drill-version))
+  (should (string-match-p "\\`[0-9]+\\.[0-9]+" org-drill-version)))
+
+(ert-deftest test-org-drill-version-command-returns-the-version ()
+  "Calling the command returns the version string."
+  (should (equal org-drill-version (org-drill-version))))
+
+(ert-deftest test-org-drill-version-command-is-interactive ()
+  "The version reporter is an interactive command."
+  (should (commandp 'org-drill-version)))
+
+(provide 'test-org-drill-version)
+
+;;; test-org-drill-version.el ends here