test(processes): retarget the update_process patch at get_note_for_user

Run 2899: 1 failed, 402 passed. test_update_process_rejects_non_process_note
still patched notes.get_note, which update_process no longer calls now that it
resolves shares — so the real get_note_for_user ran and reached for a database.

Retargeted at get_note_for_user (which returns (note, permission)), and added the
companion case the new behaviour deserves: a viewer grant is refused with the
read-only reason and never reaches update_note.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RLwAaV4DQEmVyn496HnEvt

tests/test_mcp_tool_processes.py

@@ -89,14 +89,34 @@ async def test_get_process_not_found_raises():
 
 @pytest.mark.asyncio
 async def test_update_process_rejects_non_process_note():
+    # Resolves share-aware now, so the patch target is get_note_for_user, which
+    # returns (note, permission).
     plain = _fake_note(id=3, note_type="note")
-    with patch("scribe.services.notes.get_note",
+    plain.deleted_at = None
-               AsyncMock(return_value=plain)):
+    with patch("scribe.services.notes.get_note_for_user",
+               AsyncMock(return_value=(plain, "owner"))):
         from scribe.mcp.tools.processes import update_process
         with pytest.raises(ValueError):
             await update_process(process_id=3, title="x")
 
 
+@pytest.mark.asyncio
+async def test_update_process_refuses_a_read_only_share_with_the_reason():
+    """An editor grant lets the holder edit someone else's process; a viewer
+    grant must be refused, and saying "not found" about a process the caller can
+    open would just send them looking for a missing id."""
+    theirs = _fake_note(id=5, user_id=9)
+    theirs.deleted_at = None
+    with patch("scribe.services.notes.get_note_for_user",
+               AsyncMock(return_value=(theirs, "viewer"))), \
+         patch("scribe.services.access.can_write_note", AsyncMock(return_value=False)), \
+         patch("scribe.services.notes.update_note", AsyncMock()) as mock_update:
+        from scribe.mcp.tools.processes import update_process
+        with pytest.raises(ValueError, match="read-only"):
+            await update_process(process_id=5, title="x")
+    mock_update.assert_not_awaited()
+
+
 def test_register_attaches_four_tools():
     from scribe.mcp.tools import processes
     names: list[str] = []