feat(install-lang): seed a neutral CLAUDE.md when a bundle ships none

install-lang only seeded CLAUDE.md if the chosen bundle shipped one. elisp and go do, python and typescript don't. A project installing a template-less bundle got no CLAUDE.md, and a multi-bundle install inherited whichever bundle shipped one. A bash project that installed elisp and python ended up headed "Elisp project," worse than no header.

I added a language-neutral default (languages/default-CLAUDE.md) that names no language, so single-language, multi-bundle, and wrong-bundle installs all get an accurate "fill this in" header instead of a false one. Per-bundle templates still win where present. The seed-on-first-install, no-overwrite logic is unchanged.

I hardened the Makefile LANGUAGES glob to directories only so the new template file doesn't show up as a selectable language. lint covers the default. The install-lang tests cover the fallback, the bundle-wins branch, and no-overwrite.

A bash bundle is still the real gap for shell-heavy projects, filed as a backlog task.

1 files changed, 3 insertions, 0 deletions

diff --git a/scripts/lint.sh b/scripts/lint.sh
index ae30aa5..61a27a1 100755
--- a/scripts/lint.sh
+++ b/scripts/lint.sh
@@ -99,6 +99,9 @@ for claude_md in languages/*/CLAUDE.md; do
   check_md_heading "$claude_md"
 done
 
+# Language-neutral default CLAUDE.md (install-lang's fallback when a bundle ships none)
+[ -f languages/default-CLAUDE.md ] && check_md_heading languages/default-CLAUDE.md
+
 # Hook scripts
 for h in languages/*/claude/hooks/*.sh languages/*/githooks/*; do
   [ -f "$h" ] || continue