fix(language-bundle): don't re-drop the coverage fragment once adopted

The startup bundle sync re-dropped from-rulesets-coverage-makefile.txt into a project's inbox on every run, even after the project had adopted the targets. inbox_drop only treated the fragment as adopted if coverage-makefile.txt still sat at the project root or waited in the inbox. But install-lang tells users the opposite: copy the targets into your Makefile, then delete the fragment. So a project that followed the documented path got the drop re-suggested forever (deleted three sessions running in one case).

I guarded the drop so a project Makefile that already defines the distinctive coverage-summary target counts as adopted. The check lives at the call site, keeping inbox_drop generic. Added two bats cases: targets-in-Makefile suppresses the drop, an unrelated Makefile still gets it.

1 files changed, 24 insertions, 0 deletions

diff --git a/scripts/tests/sync-language-bundle.bats b/scripts/tests/sync-language-bundle.bats
index 5e3b912..1871444 100644
--- a/scripts/tests/sync-language-bundle.bats
+++ b/scripts/tests/sync-language-bundle.bats
@@ -182,6 +182,30 @@ install_team_overlay() {
   [[ "$output" != *"inbox"* ]]
 }
 
+@test "sync: targets copied into the project Makefile count as adopted, no re-drop" {
+  # The documented adoption path (install-lang: "copy its targets into your
+  # Makefile") leaves no fragment at root and no inbox copy. A project that did
+  # this and deleted the fragment must not get the drop re-suggested every run.
+  install_bundle elisp "$PROJ"
+  mkdir -p "$PROJ/.ai/inbox"
+  printf 'coverage:\n\t@true\ncoverage-summary:\n\t@true\n' > "$PROJ/Makefile"
+  run bash "$SCRIPT" "$PROJ"
+  [ "$status" -eq 0 ]
+  [ ! -f "$PROJ/.ai/inbox/from-rulesets-coverage-makefile.txt" ]
+  [[ "$output" != *"inbox"* ]]
+}
+
+@test "sync: a project Makefile without the coverage-summary target still gets the drop" {
+  # Guard against over-broad detection: an unrelated Makefile must not suppress
+  # a genuinely-unadopted fragment.
+  install_bundle elisp "$PROJ"
+  mkdir -p "$PROJ/.ai/inbox"
+  printf 'build:\n\t@true\ntest:\n\t@true\n' > "$PROJ/Makefile"
+  run bash "$SCRIPT" "$PROJ"
+  [ "$status" -eq 0 ]
+  [ -f "$PROJ/.ai/inbox/from-rulesets-coverage-makefile.txt" ]
+}
+
 # --- Surface-only: settings.json ---
 
 @test "sync: drifted settings.json is surfaced, NOT modified, exit 3" {