Broken graph editor

docs/bullet-script-graph-editor-plan.md

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+# Bullet Script Graph Editor Plan
+
+## Goals
+- Create an editor plugin in GDScript using `GraphEdit` and `GraphNode` for visual authoring of bullet scripts.
+- Support opening from `BossScript`, `BossPhase`, `BulletScript3D`, or `BulletScript`.
+- Visualize parent/child pattern relationships as linked graph nodes.
+- Keep legacy `BossPhase.Patterns` intact to avoid breaking existing compositions.
+- Introduce `BossPhase -> BulletScript3D` for flexible composition.
+- Persist graph layout metadata so graph positions remain stable across sessions.
+
+## Existing System Summary
+- `BossScript` contains phases: `Scripts/Resources/ScriptableBullets/BossScript.cs`.
+- `BossPhase` currently executes legacy `Patterns` (`Array<AttackPattern>`): `Scripts/Resources/BossPhase.cs`.
+- `BulletScript3D` and `BulletScript` are standalone pattern containers:
+  - `Scripts/Resources/BulletScripts/BulletScript3D.cs`
+  - `Scripts/Resources/BulletScript.cs`
+- Pattern composition already exists with:
+  - Sequential group: `Scripts/Resources/PatternGroup.cs`
+  - Parallel group: `Scripts/Resources/ScriptableBullets/ParallelPatternGroup.cs`
+
+## Non-Breaking Runtime Changes
+1. Add `[Export] public BulletScript3D BulletScript3D;` to `BossPhase`.
+2. Keep `Patterns` unchanged and mark as legacy with a TODO comment.
+3. In `BossPhase.Start` and `BossPhase.UpdatePhase`, prioritize `BulletScript3D` execution when assigned.
+4. Fall back to legacy `Patterns` path when `BulletScript3D` is not assigned.
+5. Add null/empty guards for robust editor/runtime behavior.
+
+## Plugin Architecture
+- New addon: `addons/bullet_script_graph_editor/`
+- Main files:
+  - `plugin.cfg`
+  - `plugin.gd` (`EditorPlugin` entry)
+  - `inspector_plugin.gd` (open-in-graph button in inspector)
+  - `ui/graph_editor_dock.tscn`
+  - `ui/graph_editor_dock.gd`
+  - `model/graph_adapter.gd`
+
+### Entry Points
+- Bottom dock panel for direct resource picking/opening.
+- Inspector button for fast open from selected resource.
+
+### Graph Mapping Rules
+- `BossScript` -> phase chain nodes.
+- `BossPhase` ->
+  - legacy pattern chain lane from `Patterns`
+  - optional linked `BulletScript3D` lane.
+- `BulletScript3D` / `BulletScript` -> ordered pattern chain.
+- `PatternGroup` and `ParallelPatternGroup` -> composite nodes with child links.
+
+### Persistence
+- Store node graph position metadata on resources using editor metadata keys.
+- Use stable node IDs to restore positions across reopen.
+
+## Validation Checklist
+1. Enable plugin and confirm dock is visible.
+2. Open `Resources/BossPhases/Rumia_Boss_Script_3D.tres` and verify phase/pattern graph.
+3. Open `Resources/BulletScripts/Danmaku_Room_1.tres` and verify pattern chain graph.
+4. Save, reopen, and verify node positions persist.
+5. Run build:
+   - `dotnet build k:/godot/cirno/Cirno.csproj -c Debug -v normal -p:GodotTargetPlatform=windows`
+
+## Out-of-Scope for Initial Cut
+- Removing legacy `Patterns`.
+- Full simulation/debug playback inside the graph UI.
+- Automatic bulk migration of all existing resources.