Extract retained stroke preview setup planner

docs/modernization/debt.md

@@ -18,6 +18,14 @@ agent or engineer to remove them without reconstructing context from chat.
 
 ## Recent Reductions
 
+- 2026-06-13: DEBT-0036 was narrowed again. `NodeStrokePreview::draw_stroke_immediate()`
+  now routes retained preview stroke max-size fallback, dual-preview max-size
+  derivation, pattern-scale flips, and Bezier preview-point generation through
+  `plan_legacy_node_stroke_preview_stroke_setup(...)`; compositor coverage now
+  also locks the retained stroke-setup curve/pressure intent and
+  pass-sequence validation short-circuit behavior. Brush object mutation,
+  camera wiring, retained `Stroke` population, and all live GL execution
+  remain in the legacy preview node.
 - 2026-06-13: DEBT-0036 was narrowed again. `Canvas::draw_merge()` per-layer
   blend composite now routes merge-RTT unbind, shader setup, optional
   destination-copy feedback, draw, and cleanup ordering through

docs/modernization/roadmap.md

@@ -3155,6 +3155,12 @@ Results:
   dual-pass/background/main-pass/final-composite/copy-back ordering, while the
   remaining local preview ownership is concentrated around `stroke_draw_mix()`
   setup/execution.
+- `NodeStrokePreview::draw_stroke_immediate()` now routes preview stroke
+  max-size fallback, dual-preview max-size derivation, pattern-scale flips,
+  and Bezier preview-point generation through
+  `plan_legacy_node_stroke_preview_stroke_setup(...)`, while brush mutation,
+  camera wiring, retained `Stroke` population, and live GL execution remain in
+  the preview node.
 - `NodeStrokePreview::stroke_draw_mix()` now shares one local helper for mixer
   framebuffer bind/unbind, viewport/scissor/blend state, texture-slot
   binding, and final plane draw, while material planning and shader uniform

docs/modernization/tasks.md

@@ -509,6 +509,16 @@ Done Checks:
 
 Progress Notes:
 
+- 2026-06-13: `NodeStrokePreview::draw_stroke_immediate()` now routes preview
+  stroke max-size fallback, dual-preview max-size derivation, pattern-scale
+  flips, and Bezier preview-point generation through
+  `plan_legacy_node_stroke_preview_stroke_setup(...)`; compositor coverage now
+  also locks the retained stroke-setup curve/pressure intent and
+  pass-sequence request-validation short-circuit behavior. The preview node
+  still owns brush object mutation, camera wiring, retained `Stroke`
+  population, and live GL execution. Next slice should target the remaining
+  higher-level preview pass orchestration seam without reopening landed
+  sample, mix, pass-sequence, or final-composite helpers.
 - 2026-06-13: `Canvas::draw_merge()` per-layer blend composite now routes
   merge-RTT unbind, shader setup, optional destination-copy feedback, draw,
   and cleanup ordering through