fix: Preserve Actor input-schema validation keywords

[Ayush7614]

Summary

• Keep Actor-declared JSON Schema validation keywords (minimum, maximum, minLength, maxLength, minItems, maxItems, exclusive bounds, uniqueItems, pattern) through filterSchemaProperties.
• Only emit keys whose upstream value is defined — no more phantom default: undefined on every property.
• Extend SchemaProperties so the type matches what AJV and tools/list actually need.

Why

filterSchemaProperties whitelisted only title/description/enum/type/default/prefill/properties/items/required. Real Actor schemas declare bounds (e.g. maxResults maximum: 100), but MCP-side AJV never saw them, so out-of-range inputs reached Apify runs and failed late. Agents also never saw those constraints in tools/list.

Test plan

• pnpm run type-check
• pnpm run lint
• pnpm run test:unit (new filter + AJV enforcement cases; updated transform assertions)
• pnpm run format / pnpm run check:agents
• Spot-check tools/list for an Actor with maximum/minLength and confirm bounds appear