feat: implement scope parser with CIDR, domain, wildcard, and exclusion support

[dmchaledev]

Full zero-dependency TypeScript implementation:

• src/types.ts: ParsedEntry, NormalizedScopeJSON interfaces
• src/parse.ts: ipToInt, intToIp, prefixToMask, parseEntry (IPv4, CIDR, domain, wildcard, exclusion)
• src/NormalizedScope.ts: NormalizedScope class with .includes()/.excludes()/.toCIDR()/.toJSON()
• src/index.ts: parseScope() convenience function + re-exports
• 20 vitest tests across parse.test.ts and scope.test.ts (all passing)
• tsconfig: skipLibCheck, @types/node, excludes tests from dist build
• .eslintrc.cjs + vitest.config.ts