Add comprehensive test suite achieving 99% code coverage

Added 35 test files with 502 tests covering all Python modules including
API routes, ORM models, splendor game logic/TUI, heater controller,
weather service, NixOS installer, ZFS dataset management, and utilities.
Coverage improved from 11% to 99% (2540/2564 statements covered).

https://claude.ai/code/session_01SVzgLDUS1Cdc4eh1ijETTh

tests/test_installer.py

@@ -0,0 +1,191 @@
+"""Tests for python/installer modules."""
+
+from __future__ import annotations
+
+import curses
+from unittest.mock import MagicMock, patch
+
+import pytest
+
+from python.installer.tui import (
+    Cursor,
+    State,
+    calculate_device_menu_padding,
+    get_device,
+)
+
+
+# --- Cursor tests ---
+
+
+def test_cursor_init() -> None:
+    """Test Cursor initialization."""
+    c = Cursor()
+    assert c.get_x() == 0
+    assert c.get_y() == 0
+    assert c.height == 0
+    assert c.width == 0
+
+
+def test_cursor_set_height_width() -> None:
+    """Test Cursor set_height and set_width."""
+    c = Cursor()
+    c.set_height(100)
+    c.set_width(200)
+    assert c.height == 100
+    assert c.width == 200
+
+
+def test_cursor_bounce_check() -> None:
+    """Test Cursor bounce checks."""
+    c = Cursor()
+    c.set_height(10)
+    c.set_width(20)
+
+    assert c.x_bounce_check(-1) == 0
+    assert c.x_bounce_check(25) == 19
+    assert c.x_bounce_check(5) == 5
+
+    assert c.y_bounce_check(-1) == 0
+    assert c.y_bounce_check(15) == 9
+    assert c.y_bounce_check(5) == 5
+
+
+def test_cursor_set_x_y() -> None:
+    """Test Cursor set_x and set_y."""
+    c = Cursor()
+    c.set_height(10)
+    c.set_width(20)
+    c.set_x(5)
+    c.set_y(3)
+    assert c.get_x() == 5
+    assert c.get_y() == 3
+
+
+def test_cursor_set_x_y_bounds() -> None:
+    """Test Cursor set_x and set_y with bounds."""
+    c = Cursor()
+    c.set_height(10)
+    c.set_width(20)
+    c.set_x(-5)
+    assert c.get_x() == 0
+    c.set_y(100)
+    assert c.get_y() == 9
+
+
+def test_cursor_move_up() -> None:
+    """Test Cursor move_up."""
+    c = Cursor()
+    c.set_height(10)
+    c.set_width(20)
+    c.set_y(5)
+    c.move_up()
+    assert c.get_y() == 4
+
+
+def test_cursor_move_down() -> None:
+    """Test Cursor move_down."""
+    c = Cursor()
+    c.set_height(10)
+    c.set_width(20)
+    c.set_y(5)
+    c.move_down()
+    assert c.get_y() == 6
+
+
+def test_cursor_move_left() -> None:
+    """Test Cursor move_left."""
+    c = Cursor()
+    c.set_height(10)
+    c.set_width(20)
+    c.set_x(5)
+    c.move_left()
+    assert c.get_x() == 4
+
+
+def test_cursor_move_right() -> None:
+    """Test Cursor move_right."""
+    c = Cursor()
+    c.set_height(10)
+    c.set_width(20)
+    c.set_x(5)
+    c.move_right()
+    assert c.get_x() == 6
+
+
+def test_cursor_navigation() -> None:
+    """Test Cursor navigation with arrow keys."""
+    c = Cursor()
+    c.set_height(10)
+    c.set_width(20)
+    c.set_x(5)
+    c.set_y(5)
+
+    c.navigation(curses.KEY_UP)
+    assert c.get_y() == 4
+    c.navigation(curses.KEY_DOWN)
+    assert c.get_y() == 5
+    c.navigation(curses.KEY_LEFT)
+    assert c.get_x() == 4
+    c.navigation(curses.KEY_RIGHT)
+    assert c.get_x() == 5
+
+
+def test_cursor_navigation_unknown_key() -> None:
+    """Test Cursor navigation with unknown key (no-op)."""
+    c = Cursor()
+    c.set_height(10)
+    c.set_width(20)
+    c.set_x(5)
+    c.set_y(5)
+    c.navigation(999)  # Unknown key
+    assert c.get_x() == 5
+    assert c.get_y() == 5
+
+
+# --- State tests ---
+
+
+def test_state_init() -> None:
+    """Test State initialization."""
+    s = State()
+    assert s.key == 0
+    assert s.swap_size == 0
+    assert s.reserve_size == 0
+    assert s.selected_device_ids == set()
+    assert s.show_swap_input is False
+    assert s.show_reserve_input is False
+
+
+def test_state_get_selected_devices() -> None:
+    """Test State.get_selected_devices."""
+    s = State()
+    s.selected_device_ids = {"/dev/sda", "/dev/sdb"}
+    result = s.get_selected_devices()
+    assert isinstance(result, tuple)
+    assert set(result) == {"/dev/sda", "/dev/sdb"}
+
+
+# --- get_device tests ---
+
+
+def test_get_device() -> None:
+    """Test get_device parses device string."""
+    raw = 'NAME="/dev/sda" SIZE="100G" TYPE="disk" MOUNTPOINTS=""'
+    device = get_device(raw)
+    assert device["name"] == "/dev/sda"
+    assert device["size"] == "100G"
+    assert device["type"] == "disk"
+
+
+# --- calculate_device_menu_padding ---
+
+
+def test_calculate_device_menu_padding() -> None:
+    """Test calculate_device_menu_padding."""
+    devices = [
+        {"name": "/dev/sda", "size": "100G"},
+        {"name": "/dev/nvme0n1", "size": "500G"},
+    ]
+    padding = calculate_device_menu_padding(devices, "name", 2)
+    assert padding == len("/dev/nvme0n1") + 2