fix(inbox-send): preserve dots in copied filenames

send_file ran filenames through slugify(), which flattens dots to hyphens. That corrupts the engine.plugin.org plugin-namespace convention: triage-intake.personal-gmail.org arrived as triage-intake-personal-gmail.org, which breaks the engine's triage-intake.*.org glob and the routing that depends on the first dot.

I added slugify_filename() for filename stems. It keeps dots, hyphens, underscores, and case, collapses only whitespace runs to hyphens, and truncates on a separator boundary. The prose --text path still uses slugify().

1 files changed, 28 insertions, 0 deletions

diff --git a/.ai/scripts/tests/test_inbox_send.py b/.ai/scripts/tests/test_inbox_send.py
index 597a7e9..a0094dc 100644
--- a/.ai/scripts/tests/test_inbox_send.py
+++ b/.ai/scripts/tests/test_inbox_send.py
@@ -248,6 +248,34 @@ class TestInboxSendFile:
         files = list((tmp_path / "projects" / "target" / "inbox").iterdir())
         assert "branching-strategy-notes" in files[0].name
 
+    def test_inbox_send_file_preserves_dots_in_basename(self, project_root, run_script, tmp_path):
+        """Boundary: a dotted stem keeps its dots — the engine.plugin.org plugin namespace must survive transit."""
+        project_root("target")
+        cwd = project_root("source")
+        src = tmp_path / "triage-intake.personal-gmail.org"
+        src.write_text("plugin")
+        run_script(
+            ["target", "--file", str(src)],
+            cwd=cwd, roots=[tmp_path / "projects"],
+        )
+        files = list((tmp_path / "projects" / "target" / "inbox").iterdir())
+        assert len(files) == 1
+        assert _slug_from(files, "source") == "triage-intake.personal-gmail"
+        assert files[0].suffix == ".org"
+
+    def test_inbox_send_file_spaces_become_hyphens(self, project_root, run_script, tmp_path):
+        """Normal: whitespace in a filename stem still collapses to hyphens; dots are what's preserved, not spaces."""
+        project_root("target")
+        cwd = project_root("source")
+        src = tmp_path / "meeting notes draft.org"
+        src.write_text("x")
+        run_script(
+            ["target", "--file", str(src)],
+            cwd=cwd, roots=[tmp_path / "projects"],
+        )
+        files = list((tmp_path / "projects" / "target" / "inbox").iterdir())
+        assert _slug_from(files, "source") == "meeting-notes-draft"
+
     def test_inbox_send_file_name_override(self, project_root, run_script, tmp_path):
         """Normal: --name overrides the basename-derived slug; extension preserved."""
         project_root("target")