Make scene layer random seeds reproducible

docs/superpowers/plans/2026-07-01-scene-layer-seed-simplification.md

@@ -0,0 +1,128 @@
+# Scene Layer Seed Simplification Implementation Plan
+
+> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.
+
+**Goal:** Make `SxCPSceneLayerSeedOptions` use the visible node seed for `random` mode so prompt clothing/content choices are reproducible from the workflow.
+
+**Architecture:** Keep the existing scene seed pipeline. Change only layer seed option resolution so `random` no longer replaces the visible seed with a hidden `SystemRandom` value. Preserve existing `seed_trace` and scene pair metadata behavior.
+
+**Tech Stack:** Python ComfyUI custom nodes, existing smoke tests in `tools/prompt_smoke.py`.
+
+---
+
+### Task 1: Add Failing Smoke Coverage
+
+**Files:**
+- Modify: `tools/prompt_smoke.py`
+
+- [ ] **Step 1: Add assertions to `smoke_node_scene_chain_registration`**
+
+Add a small check after the node registry assertions or near the existing scene layer seed checks:
+
+```python
+    random_seed_options = nodes["SxCPSceneLayerSeedOptions"]().build(
+        "softcore_branch",
+        "random",
+        123456789,
+        "content_pose",
+        "same_for_all_rows",
+        "replace_layer",
+    )[0]
+    fixed_seed_options = nodes["SxCPSceneLayerSeedOptions"]().build(
+        "softcore_branch",
+        "fixed",
+        123456789,
+        "content_pose",
+        "same_for_all_rows",
+        "replace_layer",
+    )[0]
+    random_seed_item = json.loads(random_seed_options)["items"][0]
+    fixed_seed_item = json.loads(fixed_seed_options)["items"][0]
+    _expect(random_seed_item.get("seed") == 123456789, "Scene random layer seed should use the visible node seed")
+    _expect(
+        random_seed_item.get("seed") == fixed_seed_item.get("seed"),
+        "Scene random and fixed layer seeds should match when the visible seed matches",
+    )
+```
+
+- [ ] **Step 2: Run focused smoke test and verify it fails**
+
+Run:
+
+```bash
+python tools/prompt_smoke.py --case node_scene_chain_registration --quiet
+```
+
+Expected: FAIL with `Scene random layer seed should use the visible node seed`.
+
+### Task 2: Make Visible Seed Authoritative
+
+**Files:**
+- Modify: `node_scene.py`
+
+- [ ] **Step 1: Remove hidden random replacement**
+
+In `_layer_seed_options_json`, remove the `SystemRandom` override:
+
+```python
+    resolved_seed = max(0, min(0xFFFFFFFF, int(seed)))
+```
+
+The `if seed_mode == "random": ...` branch should be deleted. Leave `seed_mode` in metadata unchanged for compatibility.
+
+- [ ] **Step 2: Run focused smoke test and verify it passes**
+
+Run:
+
+```bash
+python tools/prompt_smoke.py --case node_scene_chain_registration --quiet
+```
+
+Expected: `OK: smoke passed (1 cases).`
+
+### Task 3: Verify and Commit
+
+**Files:**
+- Verify: `node_scene.py`
+- Verify: `tools/prompt_smoke.py`
+- Commit: implementation and plan file
+
+- [ ] **Step 1: Compile changed Python files**
+
+Run:
+
+```bash
+python -m py_compile node_scene.py tools/prompt_smoke.py
+```
+
+Expected: exit code 0.
+
+- [ ] **Step 2: Run full smoke suite**
+
+Run:
+
+```bash
+python tools/prompt_smoke.py --quiet
+```
+
+Expected: either all smoke cases pass, or only the existing unrelated `krea2_prompt_guide_policy` methodology-memory failure remains.
+
+- [ ] **Step 3: Review diff**
+
+Run:
+
+```bash
+git --git-dir=.git-real --work-tree=. diff --stat
+git --git-dir=.git-real --work-tree=. diff -- node_scene.py tools/prompt_smoke.py
+```
+
+Expected: only the random seed behavior and its smoke coverage changed.
+
+- [ ] **Step 4: Commit implementation**
+
+Run:
+
+```bash
+git --git-dir=.git-real --work-tree=. add node_scene.py tools/prompt_smoke.py docs/superpowers/plans/2026-07-01-scene-layer-seed-simplification.md
+git --git-dir=.git-real --work-tree=. commit -m "Make scene layer random seeds reproducible"
+```

node_scene.py

@@ -446,8 +446,6 @@ def _layer_seed_options_json(
     if combine_mode == "replace_layer":
         items = [item for item in _seed_option_items(seed_options) if item.get("layer") != layer]
     resolved_seed = max(0, min(0xFFFFFFFF, int(seed)))
-    if seed_mode == "random":
-        resolved_seed = random.SystemRandom().randint(0, 0xFFFFFFFF)
     items.append(
         {
             "layer": layer,

tools/prompt_smoke.py

@@ -15980,6 +15980,32 @@ def smoke_node_scene_chain_registration() -> None:
         _expect(node_name in sxcp_nodes.NODE_DISPLAY_NAME_MAPPINGS, f"{node_name} missing from display registry")
 
     nodes = sxcp_nodes.NODE_CLASS_MAPPINGS
+    random_seed_options = nodes["SxCPSceneLayerSeedOptions"]().build(
+        "softcore_branch",
+        "random",
+        123456789,
+        "content_pose",
+        "same_for_all_rows",
+        "replace_layer",
+    )[0]
+    fixed_seed_options = nodes["SxCPSceneLayerSeedOptions"]().build(
+        "softcore_branch",
+        "fixed",
+        123456789,
+        "content_pose",
+        "same_for_all_rows",
+        "replace_layer",
+    )[0]
+    random_seed_item = json.loads(random_seed_options)["items"][0]
+    fixed_seed_item = json.loads(fixed_seed_options)["items"][0]
+    _expect(
+        random_seed_item.get("seed") == 123456789,
+        "Scene random layer seed should use the visible node seed",
+    )
+    _expect(
+        random_seed_item.get("seed") == fixed_seed_item.get("seed"),
+        "Scene random and fixed layer seeds should match when the visible seed matches",
+    )
     scene, start_summary, _start_metadata = nodes["SxCPSceneStart"]().build(
         1,
         41,