refactor(ai-vterm): rename Claude-specific names to a generic "agent"

I may add other terminal agents to this launcher (aider, an open-source LLM TUI), so the buffer prefix, the user knob, and the internal helpers shouldn't say "Claude". The module name (ai-vterm) and the `cj/ai-vterm-*` customs were already generic. This finishes the job:

- buffer prefix `claude [<basename>]` -> `agent [<basename>]` (the `defconst` and the matching display-buffer-alist regex move together)
- `cj/ai-vterm-claude-command` -> `cj/ai-vterm-agent-command` (the default still runs the `claude` CLI, with a docstring note on swapping it)
- `cj/--ai-vterm-claude-buffers` / `-displayed-claude-window` / `-reuse-existing-claude` -> `-agent-*`, and their test files renamed to match
- prose in the module commentary and docstrings, plus the matching test docstrings and buffer-name literals

`vterm-config.el` hardcodes the same buffer prefix in `cj/--vterm-toggle-buffer-p` (F12 excludes agent buffers from its candidate set), so that literal moved too. Collapsing it into the shared `cj/--ai-vterm-name-prefix` is a cleanup for another day.

After a reload, a project's buffer opens as `agent [foo]` instead of `claude [foo]`. Old buffers keep their names until killed. I also corrected two stale `eshell-vterm-config.el` references in ai-vterm.el docstrings (that module was split into `vterm-config.el`).

Two things keep saying "Claude": the `cj/ai-vterm-agent-command` default value (the actual CLI), and the "Claude Code" example in `vterm-config.el`'s cursor-restore docstring (a concrete TUI example, not branding).

90 tests pass. `make validate-modules` clean.

1 files changed, 20 insertions, 20 deletions

diff --git a/tests/test-ai-vterm--pick-buffer-candidates.el b/tests/test-ai-vterm--pick-buffer-candidates.el
index ddfd7529..c32039de 100644
--- a/tests/test-ai-vterm--pick-buffer-candidates.el
+++ b/tests/test-ai-vterm--pick-buffer-candidates.el
@@ -22,57 +22,57 @@
 
 (ert-deftest test-ai-vterm--pick-buffer-candidates-empty-buffers ()
   "Boundary: empty buffer list -> empty alist regardless of shown."
-  (cj/test--kill-claude-buffers)
+  (cj/test--kill-agent-buffers)
   (should (null (cj/--ai-vterm-pick-buffer-candidates nil nil)))
   (should (null (cj/--ai-vterm-pick-buffer-candidates nil 'sentinel))))
 
 (ert-deftest test-ai-vterm--pick-buffer-candidates-shown-nil ()
   "Normal: shown is nil -> straight alist in input order, no marker."
-  (cj/test--kill-claude-buffers)
-  (let ((b1 (get-buffer-create "claude [a]"))
-        (b2 (get-buffer-create "claude [b]")))
+  (cj/test--kill-agent-buffers)
+  (let ((b1 (get-buffer-create "agent [a]"))
+        (b2 (get-buffer-create "agent [b]")))
     (unwind-protect
         (let ((result (cj/--ai-vterm-pick-buffer-candidates (list b1 b2) nil)))
-          (should (equal result `(("claude [a]" . ,b1)
-                                   ("claude [b]" . ,b2)))))
+          (should (equal result `(("agent [a]" . ,b1)
+                                   ("agent [b]" . ,b2)))))
       (kill-buffer b1)
       (kill-buffer b2))))
 
 (ert-deftest test-ai-vterm--pick-buffer-candidates-shown-promotes-non-shown ()
   "Normal: shown buffer sorts last with [shown] suffix; others first."
-  (cj/test--kill-claude-buffers)
-  (let ((b1 (get-buffer-create "claude [a]"))
-        (b2 (get-buffer-create "claude [b]"))
-        (b3 (get-buffer-create "claude [c]")))
+  (cj/test--kill-agent-buffers)
+  (let ((b1 (get-buffer-create "agent [a]"))
+        (b2 (get-buffer-create "agent [b]"))
+        (b3 (get-buffer-create "agent [c]")))
     (unwind-protect
         (let ((result (cj/--ai-vterm-pick-buffer-candidates
                        (list b1 b2 b3) b1)))
           (should (equal result
-                         `(("claude [b]" . ,b2)
-                           ("claude [c]" . ,b3)
-                           ("claude [a] [shown]" . ,b1)))))
+                         `(("agent [b]" . ,b2)
+                           ("agent [c]" . ,b3)
+                           ("agent [a] [shown]" . ,b1)))))
       (kill-buffer b1)
       (kill-buffer b2)
       (kill-buffer b3))))
 
 (ert-deftest test-ai-vterm--pick-buffer-candidates-shown-only-buffer ()
   "Boundary: shown is the only entry -> single cell with [shown] marker."
-  (cj/test--kill-claude-buffers)
-  (let ((b1 (get-buffer-create "claude [a]")))
+  (cj/test--kill-agent-buffers)
+  (let ((b1 (get-buffer-create "agent [a]")))
     (unwind-protect
         (let ((result (cj/--ai-vterm-pick-buffer-candidates (list b1) b1)))
-          (should (equal result `(("claude [a] [shown]" . ,b1)))))
+          (should (equal result `(("agent [a] [shown]" . ,b1)))))
       (kill-buffer b1))))
 
 (ert-deftest test-ai-vterm--pick-buffer-candidates-shown-not-in-buffers ()
   "Boundary: stale shown buffer not in list -> all cells are non-shown."
-  (cj/test--kill-claude-buffers)
-  (let ((b1 (get-buffer-create "claude [a]"))
-        (b-stale (get-buffer-create "claude [stale]")))
+  (cj/test--kill-agent-buffers)
+  (let ((b1 (get-buffer-create "agent [a]"))
+        (b-stale (get-buffer-create "agent [stale]")))
     (unwind-protect
         (let ((result (cj/--ai-vterm-pick-buffer-candidates
                        (list b1) b-stale)))
-          (should (equal result `(("claude [a]" . ,b1)))))
+          (should (equal result `(("agent [a]" . ,b1)))))
       (kill-buffer b1)
       (kill-buffer b-stale))))