Initial commit: Shelly Manager with Textual CLI, Streamlit UI, and comprehensive .gitignore

Shelly device management app with mDNS/subnet discovery, inventory,
configuration, and mass operations for Gen1/Gen2+ devices.

Includes .gitignore excluding runtime data (device DB, user config),
AI conversation history, build artifacts, and common Python/OS patterns.

tests/test_model_names.py

@@ -0,0 +1,45 @@
+"""Shelly internal model code → display names."""
+
+from __future__ import annotations
+
+from datetime import UTC, datetime
+
+from shelly_manager.core.model_names import (
+    format_model_for_ui,
+    format_model_plain,
+    shelly_model_display_name,
+)
+from shelly_manager.core.models import ShellyDevice
+
+
+def test_snsw_001p16eu_is_plus_1pm() -> None:
+    assert shelly_model_display_name("SNSW-001P16EU") == "Plus 1PM"
+
+
+def test_unknown_model_returns_raw() -> None:
+    assert shelly_model_display_name("UNKNOWN-XYZ") == "UNKNOWN-XYZ"
+
+
+def test_format_model_plain() -> None:
+    assert "Plus 1PM" in format_model_plain("SNSW-001P16EU")
+    assert "SNSW-001P16EU" in format_model_plain("SNSW-001P16EU")
+
+
+def test_shelly_device_model_label() -> None:
+    d = ShellyDevice(
+        id="AABBCCDDEEFF",
+        name=None,
+        mac="AA:BB:CC:DD:EE:FF",
+        ip="192.168.1.1",
+        generation=2,
+        model="SNSW-001P16EU",
+        firmware="1.0",
+        online=True,
+        last_seen=datetime.now(UTC),
+        capabilities=[],
+        status={},
+        settings={},
+    )
+    assert d.model_display_name == "Plus 1PM"
+    assert "Plus 1PM" in d.model_label
+    assert "SNSW-001P16EU" in d.model_label