fix(inbox-send): clean error on an unreadable source, dedupe overlapping roots

main caught ValueError and FileNotFoundError around the send, so an unreadable source raised a PermissionError as a raw traceback instead of the clean "inbox-send: <message>" every other failure produces. Widening the catch to OSError covers the unreadable source, the missing source, and any atomic-write failure alike.

discover_projects appended without deduping, so a roots config naming both a parent directory and one of its children listed the same project at two indices. It now dedupes on the resolved path, first-seen order preserved.

4 files changed, 118 insertions, 6 deletions

diff --git a/.ai/scripts/inbox-send.py b/.ai/scripts/inbox-send.py
index 5787a84..663efcb 100755
--- a/.ai/scripts/inbox-send.py
+++ b/.ai/scripts/inbox-send.py
@@ -70,17 +70,28 @@ def discover_projects(roots: list[Path]) -> list[Path]:
     a specific project root (included directly if it qualifies).
     """
     projects: list[Path] = []
+    seen: set[Path] = set()
+
+    def _add(p: Path) -> None:
+        # Dedupe on the resolved path: a roots config naming both a parent and
+        # one of its children would otherwise list the child project twice, at
+        # two different indices.
+        key = p.resolve()
+        if key not in seen:
+            seen.add(key)
+            projects.append(p)
+
     for root in roots:
         if not root.is_dir():
             continue
         if _is_project(root):
-            projects.append(root)
+            _add(root)
             continue
         for child in sorted(root.iterdir()):
             if not child.is_dir():
                 continue
             if _is_project(child):
-                projects.append(child)
+                _add(child)
     return projects
 
 
@@ -345,7 +356,10 @@ def main() -> int:
         else:
             assert args.file is not None
             dest = send_file(target_inbox, args.file, source_name, args.name, now)
-    except (ValueError, FileNotFoundError) as exc:
+    except (ValueError, OSError) as exc:
+        # OSError covers FileNotFoundError (missing source), PermissionError
+        # (unreadable source), and any atomic-write failure — all should
+        # surface as the clean "inbox-send: <message>" error, never a traceback.
         print(f"inbox-send: {exc}", file=sys.stderr)
         return 1
 
diff --git a/.ai/scripts/tests/test_inbox_send.py b/.ai/scripts/tests/test_inbox_send.py
index 02af23c..9b0a8c6 100644
--- a/.ai/scripts/tests/test_inbox_send.py
+++ b/.ai/scripts/tests/test_inbox_send.py
@@ -548,3 +548,45 @@ class TestAtomicWrite:
         dest = mod.send_file(inbox, src, "src", None, now)
         assert list(inbox.iterdir()) == [dest]
         assert dest.read_text() == "payload"
+
+
+class TestSmallerDefects:
+    """Two low-severity defects found reading inbox-send during the 2026-07-23
+    sweep: an unreadable source raised an uncaught traceback instead of the
+    clean error every other failure path produces, and a roots config naming
+    both a parent and one of its children listed the same project twice."""
+
+    def test_unreadable_source_gives_clean_error_not_traceback(
+        self, project_root, run_script, tmp_path
+    ):
+        project_root("sender")
+        project_root("receiver")
+        roots = [tmp_path / "projects"]
+        src = tmp_path / "secret.bin"
+        src.write_text("x")
+        src.chmod(0o000)
+        try:
+            result = run_script(
+                ["receiver", "--file", str(src)],
+                cwd=tmp_path / "projects" / "sender",
+                roots=roots,
+                expect_failure=True,
+            )
+        finally:
+            src.chmod(0o644)
+        assert result.returncode == 1
+        # The clean "inbox-send: <message>" shape, not a Python traceback.
+        assert result.stderr.startswith("inbox-send:")
+        assert "Traceback" not in result.stderr
+
+    def test_discover_projects_dedupes_parent_and_child_root(self, tmp_path):
+        mod = _load_module()
+        # A project directory, reachable both as a child of its parent root and
+        # as a root in its own right.
+        parent = tmp_path / "projects"
+        proj = parent / "app"
+        (proj / ".ai").mkdir(parents=True)
+        (proj / "inbox").mkdir()
+        found = mod.discover_projects([parent, proj])
+        resolved = [p.resolve() for p in found]
+        assert resolved.count(proj.resolve()) == 1
diff --git a/claude-templates/.ai/scripts/inbox-send.py b/claude-templates/.ai/scripts/inbox-send.py
index 5787a84..663efcb 100755
--- a/claude-templates/.ai/scripts/inbox-send.py
+++ b/claude-templates/.ai/scripts/inbox-send.py
@@ -70,17 +70,28 @@ def discover_projects(roots: list[Path]) -> list[Path]:
     a specific project root (included directly if it qualifies).
     """
     projects: list[Path] = []
+    seen: set[Path] = set()
+
+    def _add(p: Path) -> None:
+        # Dedupe on the resolved path: a roots config naming both a parent and
+        # one of its children would otherwise list the child project twice, at
+        # two different indices.
+        key = p.resolve()
+        if key not in seen:
+            seen.add(key)
+            projects.append(p)
+
     for root in roots:
         if not root.is_dir():
             continue
         if _is_project(root):
-            projects.append(root)
+            _add(root)
             continue
         for child in sorted(root.iterdir()):
             if not child.is_dir():
                 continue
             if _is_project(child):
-                projects.append(child)
+                _add(child)
     return projects
 
 
@@ -345,7 +356,10 @@ def main() -> int:
         else:
             assert args.file is not None
             dest = send_file(target_inbox, args.file, source_name, args.name, now)
-    except (ValueError, FileNotFoundError) as exc:
+    except (ValueError, OSError) as exc:
+        # OSError covers FileNotFoundError (missing source), PermissionError
+        # (unreadable source), and any atomic-write failure — all should
+        # surface as the clean "inbox-send: <message>" error, never a traceback.
         print(f"inbox-send: {exc}", file=sys.stderr)
         return 1
 
diff --git a/claude-templates/.ai/scripts/tests/test_inbox_send.py b/claude-templates/.ai/scripts/tests/test_inbox_send.py
index 02af23c..9b0a8c6 100644
--- a/claude-templates/.ai/scripts/tests/test_inbox_send.py
+++ b/claude-templates/.ai/scripts/tests/test_inbox_send.py
@@ -548,3 +548,45 @@ class TestAtomicWrite:
         dest = mod.send_file(inbox, src, "src", None, now)
         assert list(inbox.iterdir()) == [dest]
         assert dest.read_text() == "payload"
+
+
+class TestSmallerDefects:
+    """Two low-severity defects found reading inbox-send during the 2026-07-23
+    sweep: an unreadable source raised an uncaught traceback instead of the
+    clean error every other failure path produces, and a roots config naming
+    both a parent and one of its children listed the same project twice."""
+
+    def test_unreadable_source_gives_clean_error_not_traceback(
+        self, project_root, run_script, tmp_path
+    ):
+        project_root("sender")
+        project_root("receiver")
+        roots = [tmp_path / "projects"]
+        src = tmp_path / "secret.bin"
+        src.write_text("x")
+        src.chmod(0o000)
+        try:
+            result = run_script(
+                ["receiver", "--file", str(src)],
+                cwd=tmp_path / "projects" / "sender",
+                roots=roots,
+                expect_failure=True,
+            )
+        finally:
+            src.chmod(0o644)
+        assert result.returncode == 1
+        # The clean "inbox-send: <message>" shape, not a Python traceback.
+        assert result.stderr.startswith("inbox-send:")
+        assert "Traceback" not in result.stderr
+
+    def test_discover_projects_dedupes_parent_and_child_root(self, tmp_path):
+        mod = _load_module()
+        # A project directory, reachable both as a child of its parent root and
+        # as a root in its own right.
+        parent = tmp_path / "projects"
+        proj = parent / "app"
+        (proj / ".ai").mkdir(parents=True)
+        (proj / "inbox").mkdir()
+        found = mod.discover_projects([parent, proj])
+        resolved = [p.resolve() for p in found]
+        assert resolved.count(proj.resolve()) == 1