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, 18 insertions, 4 deletions

diff --git a/tests/test-ai-vterm--launch-command.el b/tests/test-ai-vterm--launch-command.el
index 7e455a8b..bac36d4e 100644
--- a/tests/test-ai-vterm--launch-command.el
+++ b/tests/test-ai-vterm--launch-command.el
@@ -55,19 +55,33 @@
              (cj/--ai-vterm-launch-command "/code/foo")))))
 
 (ert-deftest test-ai-vterm--launch-command-includes-agent-command ()
-  "Normal: the configured agent command is in the launched shell command."
+  "Normal: the configured agent command is in the launched shell command.
+The inner command is passed through `shell-quote-argument', so spaces
+are escaped (`\\\\ ') -- the regex below accepts either form."
   (let ((cj/ai-vterm-agent-command "agent --some-flag"))
     (should (string-match-p
-             "agent --some-flag"
+             "agent\\(\\\\\\)? --some-flag"
              (cj/--ai-vterm-launch-command "/code/foo")))))
 
 (ert-deftest test-ai-vterm--launch-command-tails-with-exec-bash ()
-  "Boundary: `exec bash' tails so the tmux window survives the agent exiting."
+  "Boundary: `exec bash' tails so the tmux window survives the agent exiting.
+Accepts the post-`shell-quote-argument' shape (`exec\\\\ bash')."
   (let ((cj/ai-vterm-agent-command "agent"))
     (should (string-match-p
-             "exec bash"
+             "exec\\(\\\\\\)? bash"
              (cj/--ai-vterm-launch-command "/code/foo")))))
 
+(ert-deftest test-ai-vterm--launch-command-survives-single-quote-in-agent ()
+  "Normal: a user-customized agent command containing a single quote
+shouldn't break the shell parse.  `shell-quote-argument' produces a
+valid shell token regardless of the embedded quote shape -- the
+escaping is implementation-detail, so we assert the literal words
+\"hi\" and \"there\" both appear (the space between them may be
+escaped as \\\\ )."
+  (let ((cj/ai-vterm-agent-command "agent --say 'hi there'"))
+    (let ((cmd (cj/--ai-vterm-launch-command "/code/foo")))
+      (should (string-match-p "hi\\(\\\\\\)? there" cmd)))))
+
 (ert-deftest test-ai-vterm--launch-command-handles-spaces-in-basename ()
   "Boundary: a basename with whitespace becomes hyphenated before quoting."
   (let ((cj/ai-vterm-agent-command "agent")