refactor(integrations): five hygiene fixes from the module-by-module re-review

- markdown-config.el: two related fixes on `markdown-preview'.
  First, the URL was `https://localhost:8080/imp' but simple-httpd
  serves plaintext on port 8080 -- the browser hit a TLS handshake
  against a non-TLS listener and the preview never rendered.  Changed
  to `http://' and switched from `browse-url-generic' to plain
  `browse-url' so the user's default protocol handler picks the
  browser.  Second, the function used to start the network listener
  as a side effect of opening a preview; that's split into a
  separate `cj/markdown-preview-server-start' command and
  `markdown-preview' now signals a `user-error' (with the recovery
  command in the message) when the server isn't running.

- slack-config.el: wrap the
  `which-key-add-keymap-based-replacements' call in
  `with-eval-after-load 'which-key'.  Matches the pattern other
  config modules use and means a slow / missing which-key load
  won't block requiring slack-config.

- ai-vterm.el: pass the inner shell-command-string through
  `shell-quote-argument' before wrapping in the tmux invocation.
  The default value with embedded double quotes was safe under the
  prior literal-single-quote wrap, but a user-customized
  `cj/ai-vterm-agent-command' containing a single quote silently
  broke the shell parse.  Two existing tests updated to tolerate
  the post-quote escape shape; new regression test asserts a
  single-quote-bearing custom command survives.

- eshell-config.el: scope the `TERM=xterm-256color' override to
  eshell-spawned processes only via an `eshell-mode' hook that
  prepends to a buffer-local `process-environment'.  The previous
  global `setenv' at config-time changed `TERM' for every
  subsequent `start-process' across the Emacs session, so any
  subprocess (not just eshell pipelines) inherited
  `xterm-256color' regardless of whether the receiver could
  interpret the escapes.

1 files changed, 10 insertions, 2 deletions

diff --git a/modules/ai-vterm.el b/modules/ai-vterm.el
index 18320eee..4a8f7e0e 100644
--- a/modules/ai-vterm.el
+++ b/modules/ai-vterm.el
@@ -233,11 +233,19 @@ so the tmux window survives the AI command exiting -- the session stays
 alive with a bare bash prompt for recovery, and reattach works the same way."
   (let ((session (cj/--ai-vterm-tmux-session-name dir))
         (start-dir (expand-file-name dir)))
-    (format "tmux new-session -A -s %s -n %s -c %s '%s'"
+    ;; Pass the inner shell-command-string through `shell-quote-argument'
+    ;; so any single quotes embedded in a user-customized
+    ;; `cj/ai-vterm-agent-command' don't break the literal single-quote
+    ;; wrap below.  The default value carries embedded double quotes
+    ;; (\"Read .ai/protocols.org and follow all instructions.\") which
+    ;; was safe in the prior shape but a single-quoted custom value
+    ;; silently broke the shell parse.
+    (format "tmux new-session -A -s %s -n %s -c %s %s"
             (shell-quote-argument session)
             (shell-quote-argument cj/ai-vterm-tmux-window-name)
             (shell-quote-argument start-dir)
-            (concat cj/ai-vterm-agent-command "; exec bash"))))
+            (shell-quote-argument
+             (concat cj/ai-vterm-agent-command "; exec bash")))))
 
 (defun cj/--ai-vterm-has-marker-p (dir)
   "Return non-nil when DIR contains .ai/protocols.org."