feat: GM toggle — Essence hole tracking

[Jasrags]

Toggle Candidate #15 — Essence Hole Tracking

Source: SR5 Core Rulebook
Priority: Medium
Current status: Partially toggleable (flag exists, not exposed to GM)

What it controls

Whether removing augmentations creates "essence holes" (permanently lost essence) or whether essence fully returns.

Current behavior

trackEssenceHoles: true in DEFAULT_AUGMENTATION_RULES. Logic exists in lib/rules/augmentations/essence-hole.ts. Essence hole value is always 0 in practice (not fully wired).

Toggle idea

"Essence Holes" — on (RAW, permanent loss) vs. off (essence recovers, more forgiving).

Implementation location

• lib/rules/augmentations/essence-hole.ts
• lib/rules/augmentations/validation.ts:125
• lib/rules/magic/essence-magic-link.ts:139

Tasks

• Add trackEssenceHoles to campaign settings
• Add UI toggle
• Complete essence hole wiring in essence-magic-link
• Wire campaign setting into augmentation operations
• Add tests