Name a discovered module for where it sits under the synced directory

`fluksio sync dev` refused a one-file-per-directory layout: s1..s4 each
holding `study.py` stopped the walk with "two files would both import as
'study'". The suggested `__init__.py` per study directory fixed discovery
and broke the bare `from study import ...` a test beside it does. A file is
now named for its path under the directory being synced — `dev/s1/study.py`
imports as `s1.study`, the directories between being namespace packages —
so nothing collides and nothing has to be added. A file at the root keeps
its bare name, and the generated shim follows: `import_root` walks one
directory per dotted segment and lands on the same root.

The collision message stays for the spelling that can still reach it: two
files named on the command line, each rooted at its own directory.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019Hra4ndWMCLU5F3KjUuVAc

backend/tests/test_cli.py

@@ -472,8 +472,38 @@ def test_a_study_in_a_subfolder_is_found(tmp_path) -> None:
     }
 
 
+def test_a_study_per_directory_imports_under_its_own_name(tmp_path) -> None:
+    """One `study.py` per folder is a layout people have, and it works.
+
+    Named for where each sits under the directory being synced, so nothing
+    collides and no `__init__.py` has to be added — which would break the
+    bare `from study import ...` a test beside it does.
+    """
+    import sys
+
+    from fluksio.sdk.cli import discover
+
+    for study in ("s1", "s2"):
+        (tmp_path / "dev" / study).mkdir(parents=True)
+        (tmp_path / "dev" / study / "study.py").write_text(f"VALUE = {study!r}\n")
+
+    try:
+        discover([str(tmp_path / "dev")])
+        assert sys.modules["s1.study"].VALUE == "s1"
+        assert sys.modules["s2.study"].VALUE == "s2"
+    finally:
+        for name in ("s1.study", "s2.study", "s1", "s2"):
+            sys.modules.pop(name, None)
+        sys.path[:] = [entry for entry in sys.path if entry != str(tmp_path / "dev")]
+
+
 def test_two_files_of_one_name_are_refused(tmp_path) -> None:
-    """Python keeps one module per name, and a node's body imports by it."""
+    """Python keeps one module per name, and a node's body imports by it.
+
+    Unreachable from one sync of a directory now that a file is named for
+    where it sits; this is the spelling that still gets there — two files
+    named on the command line, each rooted at its own directory.
+    """
     import pytest
 
     from fluksio.sdk import SyncError