feat(ai-vterm): add Claude launcher with vertical-split vterm

The new module picks a Claude-template project from a filtered completing-read list. It scans the same roots the `ai` shell launcher uses, then opens or reuses a vterm buffer named `claude [<repo>]` on the right. F9 launches it. The prior `cj/toggle-gptel` binding moves from F9 to C-F9 so both AI tools share the same physical key.

The display rule chains reuse-window -> use-some-window -> in-direction (right). The resulting window isn't dedicated. That matters because side-window dedication was breaking `buffer-move` (C-M-arrows) and `switch-to-buffer` replacement on the claude buffer. I also narrowed `vterm-toggle`'s display rule to skip `claude [` buffers. Otherwise it claimed them first with its bottom-split + dedicated treatment.

I added 23 tests across 5 files: the buffer-name transform, candidate walker, show-or-create dispatch, picker, and display rule. Design lives at docs/design/ai-vterm.org.

1 files changed, 42 insertions, 0 deletions

diff --git a/tests/test-ai-vterm--buffer-name.el b/tests/test-ai-vterm--buffer-name.el
new file mode 100644
index 00000000..95c673ba
--- /dev/null
+++ b/tests/test-ai-vterm--buffer-name.el
@@ -0,0 +1,42 @@
+;;; test-ai-vterm--buffer-name.el --- Tests for cj/--ai-vterm-buffer-name -*- lexical-binding: t; -*-
+
+;;; Commentary:
+;; Tests for the buffer-name transform.  Given an absolute project
+;; directory, the helper returns "claude [<basename>]".  The naming pattern
+;; is what the display-buffer-alist rule keys on, so a regression here
+;; silently breaks routing to the right side-window.
+
+;;; Code:
+
+(require 'ert)
+
+(add-to-list 'load-path (expand-file-name "modules" user-emacs-directory))
+(require 'ai-vterm)
+
+(ert-deftest test-ai-vterm--buffer-name-normal-project ()
+  "Normal: a typical project path yields claude [<basename>]."
+  (should (equal (cj/--ai-vterm-buffer-name "/home/cjennings/projects/foo")
+                 "claude [foo]")))
+
+(ert-deftest test-ai-vterm--buffer-name-trailing-slash ()
+  "Boundary: trailing slash collapses before basename extraction."
+  (should (equal (cj/--ai-vterm-buffer-name "/home/cjennings/projects/foo/")
+                 "claude [foo]")))
+
+(ert-deftest test-ai-vterm--buffer-name-dot-prefix-dir ()
+  "Boundary: dot-prefix dirs (.emacs.d) preserve the dot in the basename."
+  (should (equal (cj/--ai-vterm-buffer-name "/home/cjennings/.emacs.d")
+                 "claude [.emacs.d]")))
+
+(ert-deftest test-ai-vterm--buffer-name-space-in-basename ()
+  "Boundary: a space in the basename round-trips into the buffer name."
+  (should (equal (cj/--ai-vterm-buffer-name "/tmp/my work")
+                 "claude [my work]")))
+
+(ert-deftest test-ai-vterm--buffer-name-deeply-nested ()
+  "Normal: only the last path component is used."
+  (should (equal (cj/--ai-vterm-buffer-name "/a/b/c/d/e/leaf")
+                 "claude [leaf]")))
+
+(provide 'test-ai-vterm--buffer-name)
+;;; test-ai-vterm--buffer-name.el ends here