First commit with entire first rendition of the project

tests/test_mqtt.py

@@ -0,0 +1,15 @@
+from spectra.mqtt import _lookup_image_path, _db_path
+
+
+class TestDbPath:
+    def test_db_path_ends_web_db(self):
+        path = _db_path()
+        assert path.endswith("web.db")
+
+
+class TestLookupImagePath:
+    def test_nonexistent_id_returns_none(self):
+        assert _lookup_image_path(99999) is None
+
+    def test_negative_id_returns_none(self):
+        assert _lookup_image_path(-1) is None