[igorDykhta]

PMTiles returns decoded browser images, so enabled hover previously found no pixels despite a loaded tile. Read RGBA pixels lazily through a canvas and cache them weakly per immutable tile image. Raw/scientific bands are unchanged; unavailable or security-blocked readback stays unavailable.

Tests exercise the tile loader → viewport cache → hover path, coordinate selection, opt-in behavior, caching/replacement, transparent pixels, raw buffers and SecurityError. Canvas readback is mocked in the local Node suite; native ImageBitmap decoding has not been exercised.

Verification: PASS targeted Tape (387 assertions), changed-file ESLint/Prettier and diff whitespace. FAILED as expected against unchanged master (regression reproduction). PASS full yarn agent:verify on Node 24.21.0 (initial sandbox attempt failed because MCP test listeners could not bind localhost; rerun with test permissions passed). PASS independent read-only review; no actionable findings.

Review:

• RGBA display values and readback/cache lifetime
• Security/unavailable-canvas fallback and regression coverage

[Copilot]

🟢 Approval recommended

No active review issues remain, although tests were not run during review and native ImageBitmap decoding remains untested.

No open issues 🎉

What changed in this PR

Fixes raster-tile hover sampling for decoded PMTiles images by reading RGBA pixels through a canvas, while preserving raw/scientific band sampling.

Changes:

• Reads pixels lazily and caches results weakly per image, including unavailable or security-blocked readbacks.
• Adds regression coverage for the loader-to-hover flow, coordinate selection, opt-in behavior, caching, image replacement, transparency, and raw buffers.

Verification: NOT RUN during this review. Canvas readback is mocked in the added tests; native ImageBitmap decoding remains untested.

File	Description
test/​browser/​layer-tests/​raster-tile-layer-specs.js	Adds decoded-image hover and fallback regression tests.
src/​layers/​src/​raster-tile/​raster-tile-identify.ts	Adds lazy canvas readback and weak per-image pixel caching.

_{Review effort: Balanced}