Add Number Convert node (#13041)

* Add Number Convert node for unified numeric type conversion

Consolidates fragmented IntToFloat/FloatToInt nodes (previously only
available via third-party packs like ComfyMath, FillNodes, etc.) into
a single core node.

- Single input accepting INT, FLOAT, STRING, and BOOL types
- Two outputs: FLOAT and INT
- Conversion: bool→0/1, string→parsed number, float↔int standard cast
- Follows Math Expression node patterns (comfy_api, io.Schema, etc.)

Refs: COM-16925

* Register nodes_number_convert.py in extras_files list

Without this entry in nodes.py, the Number Convert node file
would not be discovered and loaded at startup.

* Add isfinite guard, exception chaining, and unit tests for Number Convert node

- Add math.isfinite() check to prevent int() crash on inf/nan string inputs
- Use 'from None' for cleaner exception chaining on string parse failure
- Add 21 unit tests covering all input types and error paths

tests-unit/comfy_extras_test/nodes_number_convert_test.py

@@ -0,0 +1,123 @@
+import pytest
+from unittest.mock import patch, MagicMock
+
+mock_nodes = MagicMock()
+mock_nodes.MAX_RESOLUTION = 16384
+mock_server = MagicMock()
+
+with patch.dict("sys.modules", {"nodes": mock_nodes, "server": mock_server}):
+    from comfy_extras.nodes_number_convert import NumberConvertNode
+
+
+class TestNumberConvertExecute:
+    @staticmethod
+    def _exec(value) -> object:
+        return NumberConvertNode.execute(value)
+
+    # --- INT input ---
+
+    def test_int_input(self):
+        result = self._exec(42)
+        assert result[0] == 42.0
+        assert result[1] == 42
+
+    def test_int_zero(self):
+        result = self._exec(0)
+        assert result[0] == 0.0
+        assert result[1] == 0
+
+    def test_int_negative(self):
+        result = self._exec(-7)
+        assert result[0] == -7.0
+        assert result[1] == -7
+
+    # --- FLOAT input ---
+
+    def test_float_input(self):
+        result = self._exec(3.14)
+        assert result[0] == 3.14
+        assert result[1] == 3
+
+    def test_float_truncation_toward_zero(self):
+        result = self._exec(-2.9)
+        assert result[0] == -2.9
+        assert result[1] == -2  # int() truncates toward zero, not floor
+
+    def test_float_output_type(self):
+        result = self._exec(5)
+        assert isinstance(result[0], float)
+
+    def test_int_output_type(self):
+        result = self._exec(5.7)
+        assert isinstance(result[1], int)
+
+    # --- BOOL input ---
+
+    def test_bool_true(self):
+        result = self._exec(True)
+        assert result[0] == 1.0
+        assert result[1] == 1
+
+    def test_bool_false(self):
+        result = self._exec(False)
+        assert result[0] == 0.0
+        assert result[1] == 0
+
+    # --- STRING input ---
+
+    def test_string_integer(self):
+        result = self._exec("42")
+        assert result[0] == 42.0
+        assert result[1] == 42
+
+    def test_string_float(self):
+        result = self._exec("3.14")
+        assert result[0] == 3.14
+        assert result[1] == 3
+
+    def test_string_negative(self):
+        result = self._exec("-5.5")
+        assert result[0] == -5.5
+        assert result[1] == -5
+
+    def test_string_with_whitespace(self):
+        result = self._exec("  7.0  ")
+        assert result[0] == 7.0
+        assert result[1] == 7
+
+    def test_string_scientific_notation(self):
+        result = self._exec("1e3")
+        assert result[0] == 1000.0
+        assert result[1] == 1000
+
+    # --- STRING error paths ---
+
+    def test_empty_string_raises(self):
+        with pytest.raises(ValueError, match="Cannot convert empty string"):
+            self._exec("")
+
+    def test_whitespace_only_string_raises(self):
+        with pytest.raises(ValueError, match="Cannot convert empty string"):
+            self._exec("   ")
+
+    def test_non_numeric_string_raises(self):
+        with pytest.raises(ValueError, match="Cannot convert string to number"):
+            self._exec("abc")
+
+    def test_string_inf_raises(self):
+        with pytest.raises(ValueError, match="non-finite"):
+            self._exec("inf")
+
+    def test_string_nan_raises(self):
+        with pytest.raises(ValueError, match="non-finite"):
+            self._exec("nan")
+
+    def test_string_negative_inf_raises(self):
+        with pytest.raises(ValueError, match="non-finite"):
+            self._exec("-inf")
+
+    # --- Unsupported type ---
+
+    def test_unsupported_type_raises(self):
+        with pytest.raises(TypeError, match="Unsupported input type"):
+            self._exec([1, 2, 3])