feat: GM toggle — Custom gameplay level values

[Jasrags]

Toggle Candidate #4 — Custom Gameplay Level Values

Source: SR5 Core Rulebook
Priority: Medium
Current status: Partially toggleable (3 presets, no custom)

What it controls

Starting karma, maximum gear availability at creation, contact point multiplier, and resource multiplier.

Current behavior

Three presets: Street (13 karma, avail 6, CHA×2), Experienced (25 karma, avail 12, CHA×3), Prime Runner (35 karma, avail 18, CHA×5, 1.5× resources). Selected via dropdown.

Toggle idea

Add a "Custom" option letting GMs set arbitrary values for each field (startingKarma, maxAvailability, contactMultiplier, resourcesMultiplier).

Implementation location

• data/editions/sr5/core-rulebook.json — gameplayLevels module
• app/campaigns/create/page.tsx:343-362 — gameplay level selector
• app/campaigns/[id]/settings/page.tsx:558-578 — editable in settings
• lib/types/edition.ts — GameplayLevelModifiers interface

Tasks

• Add "custom" option to GameplayLevel type
• Add custom gameplay level fields to campaign type
• Build UI for custom gameplay level editor
• Wire custom values into creation constraints
• Add tests