docs: add BinaryIndexDecoder implementation plan

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

docs/plans/2026-04-04-binary-index-decoder-plan.md

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+# BinaryIndexDecoder Node — Implementation Plan
+
+> **For Claude:** REQUIRED SUB-SKILL: Use superpowers:executing-plans to implement this plan task-by-task.
+
+**Goal:** Add a standalone ComfyUI node `BinaryIndexDecoder` that converts an integer index to 3 boolean outputs using binary (bit-field) encoding.
+
+**Architecture:** Single class in `project_loader.py`, no JS extension needed, no NiceGUI changes. Takes `index` INT, returns `(flag_0, flag_1, flag_2)` as BOOLEAN using bit-shift logic. Added to existing node mappings.
+
+**Tech Stack:** Python, ComfyUI node API, pytest
+
+---
+
+### Task 1: Write failing tests for BinaryIndexDecoder
+
+**Files:**
+- Modify: `tests/test_project_loader.py` (append new test class at end, before `TestNodeMappings`)
+- Modify: `tests/test_project_loader.py` — update `TestNodeMappings.test_mappings_exist` to expect 5 nodes
+
+**Step 1: Add the test class**
+
+Append this class before `TestNodeMappings` in `tests/test_project_loader.py`:
+
+```python
+class TestBinaryIndexDecoder:
+    def test_input_types(self):
+        from project_loader import BinaryIndexDecoder
+        inputs = BinaryIndexDecoder.INPUT_TYPES()
+        assert "index" in inputs["required"]
+        assert inputs["required"]["index"][0] == "INT"
+
+    def test_three_boolean_outputs(self):
+        from project_loader import BinaryIndexDecoder
+        assert BinaryIndexDecoder.RETURN_TYPES == ("BOOLEAN", "BOOLEAN", "BOOLEAN")
+        assert BinaryIndexDecoder.RETURN_NAMES == ("flag_0", "flag_1", "flag_2")
+
+    def test_category(self):
+        from project_loader import BinaryIndexDecoder
+        assert BinaryIndexDecoder.CATEGORY == "JSON Manager/utils"
+
+    def test_index_0(self):
+        from project_loader import BinaryIndexDecoder
+        assert BinaryIndexDecoder().decode(0) == (False, False, False)
+
+    def test_index_1(self):
+        from project_loader import BinaryIndexDecoder
+        assert BinaryIndexDecoder().decode(1) == (True, False, False)
+
+    def test_index_2(self):
+        from project_loader import BinaryIndexDecoder
+        assert BinaryIndexDecoder().decode(2) == (False, True, False)
+
+    def test_index_3(self):
+        from project_loader import BinaryIndexDecoder
+        assert BinaryIndexDecoder().decode(3) == (True, True, False)
+
+    def test_index_4(self):
+        from project_loader import BinaryIndexDecoder
+        assert BinaryIndexDecoder().decode(4) == (False, False, True)
+
+    def test_index_7(self):
+        from project_loader import BinaryIndexDecoder
+        assert BinaryIndexDecoder().decode(7) == (True, True, True)
+```
+
+Also update `TestNodeMappings.test_mappings_exist`:
+
+```python
+def test_mappings_exist(self):
+    from project_loader import PROJECT_NODE_CLASS_MAPPINGS, PROJECT_NODE_DISPLAY_NAME_MAPPINGS
+    assert "ProjectLoaderDynamic" in PROJECT_NODE_CLASS_MAPPINGS
+    assert "ProjectSource" in PROJECT_NODE_CLASS_MAPPINGS
+    assert "ProjectKey" in PROJECT_NODE_CLASS_MAPPINGS
+    assert "ProjectResolution" in PROJECT_NODE_CLASS_MAPPINGS
+    assert "BinaryIndexDecoder" in PROJECT_NODE_CLASS_MAPPINGS
+    assert len(PROJECT_NODE_CLASS_MAPPINGS) == 5
+    assert len(PROJECT_NODE_DISPLAY_NAME_MAPPINGS) == 5
+```
+
+**Step 2: Run tests to verify they fail**
+
+```bash
+python -m pytest tests/test_project_loader.py::TestBinaryIndexDecoder -v
+```
+
+Expected: FAIL with `ImportError: cannot import name 'BinaryIndexDecoder'`
+
+**Step 3: Commit the failing tests**
+
+```bash
+git add tests/test_project_loader.py
+git commit -m "test: add failing tests for BinaryIndexDecoder node"
+```
+
+---
+
+### Task 2: Implement BinaryIndexDecoder
+
+**Files:**
+- Modify: `project_loader.py` — add class after `ProjectResolution`, update mappings
+
+**Step 1: Add the class**
+
+Insert after the `ProjectResolution` class (before `# --- Mappings ---`) in `project_loader.py`:
+
+```python
+class BinaryIndexDecoder:
+    """Decodes an integer index into 3 boolean flags using binary (bit-field) encoding.
+
+    index 0 → (False, False, False)
+    index 1 → (True,  False, False)  # bit 0
+    index 2 → (False, True,  False)  # bit 1
+    index 3 → (True,  True,  False)  # bits 0+1
+    index 4 → (False, False, True)   # bit 2
+    ...
+    index 7 → (True,  True,  True)
+    """
+
+    @classmethod
+    def INPUT_TYPES(s):
+        return {
+            "required": {
+                "index": ("INT", {"default": 0, "min": 0, "max": 7}),
+            }
+        }
+
+    RETURN_TYPES = ("BOOLEAN", "BOOLEAN", "BOOLEAN")
+    RETURN_NAMES = ("flag_0", "flag_1", "flag_2")
+    FUNCTION = "decode"
+    CATEGORY = "JSON Manager/utils"
+    OUTPUT_NODE = False
+
+    def decode(self, index: int):
+        return (
+            bool((index >> 0) & 1),
+            bool((index >> 1) & 1),
+            bool((index >> 2) & 1),
+        )
+```
+
+**Step 2: Update mappings**
+
+In `PROJECT_NODE_CLASS_MAPPINGS`, add:
+```python
+"BinaryIndexDecoder": BinaryIndexDecoder,
+```
+
+In `PROJECT_NODE_DISPLAY_NAME_MAPPINGS`, add:
+```python
+"BinaryIndexDecoder": "Binary Index Decoder",
+```
+
+**Step 3: Run all tests**
+
+```bash
+python -m pytest tests/test_project_loader.py -v
+```
+
+Expected: all tests PASS (42 existing + 10 new = 52 total)
+
+**Step 4: Commit**
+
+```bash
+git add project_loader.py tests/test_project_loader.py
+git commit -m "feat: add BinaryIndexDecoder node (INT index → 3 BOOLEANs, binary encoding)"
+git push
+```