analysis: MVT → MapLibre Tile (MLT) tile serving analysis + MLTLayerOp

[Copilot]

Current tile serving uses MVT (binary: true) with MotionSource.timestamps stored as a separate parallel array — requiring a client-side read_parquet() join to restore per-vertex temporal data for timeline animation. MLT's m-values, column-oriented layout, and GPU-native memory format directly address this and other strata-specific pain points.

Analysis doc (docs/mlt-tile-serving-analysis.md)

• Current design audit — MVTLayerOp, the GeoArrow pipeline, and the timestamps/geometry split on MotionSource
• MLT capabilities mapped to strata's source types — m-values eliminate the Motion timestamp join; columnar layout feeds DuckDB-WASM + GeoArrow without transposition; complex types handle metadata: Record<string, unknown> natively; Z column unlocks elevation (trail profiles, canopy height)
• Gap analysis table — MVT vs MLT across compression, 3D, nested types, GPU layout, GeoParquet path, and ecosystem readiness
• 4-phase roadmap — additive MLTLayerOp → tile format negotiation in STP → m-value Motion pipeline (eliminates read_parquet() join) → elevation pipeline

Additive code changes

All changes are purely additive; all 211 existing tests unaffected.

• operators/logic.ts — MLTLayerConfig + buildMLTLayerConfig() with mValues (per-vertex timestamp extraction) and elevations (Z column) flags alongside the existing MVT builder
• operators/operators.ts — MLTLayerOp noodles.gl operator class
• operators/register.ts / operators/index.ts — registers and exports the new operator and types
• operators/__tests__/operators.test.ts — 7 tests covering null guards, flag combinations, and type discriminant

// Phase 1: opt-in per-layer, MVTLayerOp unchanged
buildMLTLayerConfig(
  'https://tiles/{z}/{x}/{y}.mlt',
  true, 1.0, 0, 22,
  true,   // mValues: embed timestamps in tile geometry (Motion sources)
  true,   // elevations: Z column for trail/canopy height
);
// → { type: 'MLTLayer', data: '...', mValues: true, elevations: true, ... }

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• maplibre.org
  • Triggering command: /home/REDACTED/work/_temp/ghcca-node/node/bin/node /home/REDACTED/work/_temp/ghcca-node/node/bin/node --enable-source-maps /home/REDACTED/work/_temp/copilot-developer-action-main/dist/index.js (dns block)
• npm.duckdb.org
  • Triggering command: /home/REDACTED/work/_temp/ghcca-node/node/bin/node node /home/REDACTED/work/strata/strata/node_modules/.bin/node-pre-gyp install --fallback-to-build (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

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