Move dashboard row processing to a web worker

[Copilot]

Moves data-intensive filtering and sorting off the UI thread while introducing a small, serializable tidy-style processing language for dashboard rows.

Changes

• Data processing

  • Adds dependency-free filter, summarize, arrange, and slice operators.
  • Supports grouped count, distinct-count, sum, mean, min, and max reductions.

• Worker integration

  • Adds module-worker RPC with request correlation, stale-response protection, and synchronous fallback.
  • Routes interactive table filtering and sorting through the worker.

• Specification

  • Documents operator shapes, execution order, aggregation semantics, structured-clone constraints, and response consistency requirements.

const operators = [
  { op: 'filter', predicates: [{ field: 'status', equals: 'open' }] },
  {
    op: 'summarize',
    by: ['repository'],
    values: [{ field: 'score', as: 'mean-score', reducer: 'mean' }]
  },
  { op: 'arrange', by: [{ field: 'mean-score', direction: 'desc' }] },
  { op: 'slice', limit: 10 }
];