Deferred feel items: true enemy body hit-flash, co-op remote swing arcs, near-impact strike beep

Clears the three follow-ups deferred by the combat-overhaul pass (c3b53cef2) + the
DR-041 "needs its own ShaderGraph slice" note. All client-only, observe-only presentation
(PresentationSystemGroup; no sim mutation, no [GhostField], no server work).

- Item 1: EnemyHitFlashSystem flashes the ACTUAL enemy body by driving the stock
  Entities-Graphics URPMaterialPropertyBaseColor override on the Rukhanka render-entity
  LEG children (root has no MaterialMeshInfo) -- NO ShaderGraph edit, no new component type.
  Lerp white->BodyFlashColor on a Health-decrease edge, decay back to white. Verified on
  screen (the AnimatedLitShader honors the per-instance _BaseColor override).
- Item 2: per-remote-player slash-arc pool in CombatFeedbackSystem, edge-detected from the
  replicated MeleeCombo on interpolated teammates (.WithDisabled<GhostOwnerIsLocal>());
  BuildSlashMesh -> BuildSlashInto(mesh,...) refactor; local player keeps _slashMr.
- Item 3: once-per-windup near-impact strike beep folded into the danger-cone loop, gated
  to a resolved local player.
- 9 new FeelConfig knobs (+ ResetDefaults).

390/390 EditMode, clean compile, zero Play exceptions. 3-lens adversarial review
(wf_8a998c6c-af9) -- no critical/major; fixed 4 minors: spurious beep at base origin before
the local player resolves, frozen tint if BodyFlashEnabled toggles off mid-flash, render-child
capture with no recovery, OnDestroy GO symmetry.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Docs/Vault/07_Sessions/2026/2026-06-27_Deferred_Feel_Items_BodyFlash_RemoteSwings_StrikeBeep.md

@@ -0,0 +1,35 @@
+---
+title: Deferred Combat-Feel Items — Body Hit-Flash + Remote Co-op Swings + Strike Beep — Build
+date: 2026-06-27
+tags: [session, combat, juice, presentation, rukhanka, entities-graphics, netcode, co-op]
+permalink: gamevault/07-sessions/2026/2026-06-27-deferred-feel-items
+---
+
+# Deferred combat-feel items — Build session
+
+Cleared the three focused follow-ups that the combat-overhaul pass had explicitly deferred (named in commit `c3b53cef2` + the [[DR-041_Slice_Combat_Depth_Enemy_Variety_Impact]] "needs its own ShaderGraph slice" note). All three are **client-only, observe-only presentation** (PresentationSystemGroup; no sim mutation, no `[GhostField]`, no server work, rollback-irrelevant).
+
+## What shipped
+- **Item 1 — TRUE body hit-flash (resolves the DR-041 deferral).** New `EnemyHitFlashSystem` (client `SystemBase`, PresentationSystemGroup). Enemies render via Rukhanka GPU deformation: the ghost ROOT holds gameplay components (`Health`, `EnemyTag`); the visible meshes are `LinkedEntityGroup` CHILD render entities (each with `Unity.Rendering.MaterialMeshInfo` + the `Shader Graphs/AnimatedLitShader` material, `_BaseColor` baked white). The system drives the **built-in Entities-Graphics per-instance override `Unity.Rendering.URPMaterialPropertyBaseColor`** (`[MaterialProperty("_BaseColor")]`) on those children: a `Health`-decrease edge lerps `_BaseColor` toward `FeelConfig.BodyFlashColor` (HDR near-white) and decays back to white. **No ShaderGraph edit, no new component type** — the original deferral assumed a custom `_Flash*` graph property was required; the reusable shortcut is the stock EG `URP*MaterialProperty*` components, which the deformation shader already honors.
+- **Item 2 — co-op REMOTE swing arcs.** `CombatFeedbackSystem` now renders each remote teammate's melee cleave: a per-remote-player pooled `RemoteSlash` (Mesh+Material+GO), edge-detected from the **replicated `MeleeCombo.SwingStartTick`** on interpolated teammates (`.WithAll<PlayerTag>().WithDisabled<GhostOwnerIsLocal>()`), reusing the refactored `BuildSlashInto(mesh, …)` sweep. The local player keeps its dedicated `_slashMr`. (`MeleeCombo` replicates to non-owners — `PlayerAnimationDriveSystem.RemoteDriveJob` already relies on this for teammate attack anim.)
+- **Item 3 — near-impact strike beep.** Folded into the existing enemy danger-cone loop (which already computes `remaining` ticks to impact): a once-per-windup `_strikeBeepClip` "dodge NOW" cue at `StrikeBeepLeadTicks` (default 8 ≈ 130 ms) before the strike lands, distance-gated to the local player.
+- 9 new `FeelConfig` knobs (+ `ResetDefaults`) covering all three.
+
+## How it went (verify ladder)
+- Drove the whole thing off an **empirical Play probe** of a live Husk: confirmed render entities are LEG children (not the root), shader = `AnimatedLitShader`, `_BaseColor` = white, and the children do **not** ship `URPMaterialPropertyBaseColor` until added.
+- **Override-works proof:** the unfocused editor kept disposing the netcode worlds mid-Play (known hazard) and server-spawned test husks were culled (spawned outside the director's bookkeeping), so I proved the mechanism on the **local player** (same `AnimatedLitShader`, persistent, centered): tinted its render children via the override → captured the Game view → **body rendered red**. Same shader ⇒ the enemy flash works. Separately confirmed `EnemyHitFlashSystem` attaches the override to all 4 enemy render children at runtime.
+- **390/390 EditMode**, clean compile, zero Play exceptions with all three paths live.
+
+## Post-impl adversarial review (`wf_8a998c6c-af9`)
+3 lenses (ECS/Entities-Graphics correctness · lifecycle/leaks/rollback · netcode-read edge cases). **No critical/major.** Fixed 4 real minors:
+- **[FIXED] Strike beep could fire spuriously at base origin** — the "no local player ⇒ `localPos`=`float3.zero` ⇒ distance gate suppresses" assumption is FALSE: origin IS the base, so base-siege enemies within 15 m would beep before the local player ghost resolves (co-op join / save-load mid-siege). Gated the beep on `_localPlayer != Entity.Null`.
+- **[FIXED] `BodyFlashEnabled` toggled off mid-flash froze an enemy tinted** (reachable via the FeelConfig tuning toggle). Added `RestoreAllToRest()` on the disable edge (settle white + clear; re-tracked on re-enable).
+- **[FIXED] `RenderKids` captured once with no recovery** — don't finalize tracking until render children exist (retry next frame if Rukhanka child setup lags ghost instantiation).
+- **[FIXED] `OnDestroy` symmetry** — also destroy the pooled remote-slash `GO`.
+- **[NOTED, no change]** hardcoded white-restore (moot — every enemy uses the Synty-atlas white-`_BaseColor` convention; documented in the system); runtime `AddComponent` fragmentation (bounded, once/child); committed-Charger lunge relies on the cone not the beep (intended).
+
+## Gotchas worth remembering
+- **Material-driven body flash on Rukhanka/EG = drive a stock `URP*MaterialProperty*` component on the render-entity CHILDREN, not a custom ShaderGraph property.** The render entities are `LinkedEntityGroup` children with `MaterialMeshInfo` (the root has none); `_BaseColor` bakes white, so flash-toward-color / decay-to-white needs no per-material rest capture. Add the override at runtime (once/child) from a client observe-only system; settle to white at rest so the override is invisible when idle.
+- **To prove an EG per-instance override is honored by a deformation shader without a stable enemy:** tint the **local player** (same material) and screenshot — the player is persistent + centered, unlike server-spawned test enemies which get culled and unlike the worlds which the unfocused editor disposes.
+
+See [[DR-041_Slice_Combat_Depth_Enemy_Variety_Impact]] (item-1 origin) · [[DR-022_Animation_Pipeline_Rukhanka_Synty]] (render-entity structure) · [[DR-038_Slice1_Combat_Readability_HUD_Declutter]] (danger-cone the beep folds into).