refactor(effects-manager): replace implicit boolean checks with EffectsState enum in render path (#886)

[deveshbervar]

Summary

Phase 1 (part 3 of 4) of #886.

Replaces implicit boolean checks in the render path with
typed EffectsState enum comparisons.

What changed

antialiasRender():

// BEFORE
if (this.selectedObjectsSet.size > 0)
else if (this.hoverOutline)

// AFTER
if (this.currentState === EffectsState.SELECTED)
else if (this.currentState === EffectsState.HOVERED)

updateSelectionPulse():

// BEFORE
if (this.selectionOutlinePass && this.selectedObjectsSet.size > 0)

// AFTER
if (this.selectionOutlinePass && this.currentState === EffectsState.SELECTED)

Scope

• effects-manager.ts only — 3 line changes
• No behavior change — all 25 existing tests pass
• Part of refactor: EffectsManager missing state model, hover color not configurable, no experiment override API #886 — Phase 1, part 3 of 4