Refactor/reduce complexity - #12

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v4, actions/setup-node@v4. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

Function 'readLoop' is hard to understand (cognitive: 18, threshold: 15). • Severity: moderate • Cyclomatic: 12 • Cognitive: 18 • Lines: 48 High cognitive complexity means deeply nested or interleaved logic. Consider flattening control flow or extracting helper functions.

Function 'useSerial' is hard to understand (cognitive: 16, threshold: 15). • Severity: moderate • Cyclomatic: 1 • Cognitive: 16 • Lines: 250 High cognitive complexity means deeply nested or interleaved logic. Consider flattening control flow or extracting helper functions.

Function '<arrow>' exceeds both complexity thresholds: • Severity: high • Cyclomatic: 21 (threshold: 20) • Cognitive: 27 (threshold: 15) • Lines: 121 Consider splitting this function into smaller, focused functions.

Function 'RealtimeChart' is hard to understand (cognitive: 27, threshold: 15). • Severity: high • Cyclomatic: 6 • Cognitive: 27 • Lines: 308 High cognitive complexity means deeply nested or interleaved logic. Consider flattening control flow or extracting helper functions.

Function 'DataLog' is hard to understand (cognitive: 30, threshold: 15). • Severity: high • Cyclomatic: 15 • Cognitive: 30 • Lines: 325 High cognitive complexity means deeply nested or interleaved logic. Consider flattening control flow or extracting helper functions.

fallow emitted 5 annotations; GitHub shows at most 10 per type per step

Fallow: Gate outcomes: passed audit-verdict.