fix(data): canonical observe.select cache key so Set includes don't collide

[krisnye]

Description

observe.select cached its per-query Observe functions under JSON.stringify({ include, options }). Because include may be a ReadonlySet — exactly the shape of archetype.components — and JSON.stringify(aSet) is always "{}", every set-based select collapsed onto a single cache key. A second set-based select was then served the first one's observe function.

This explains the reported minimal-vs-composed divergence: with a single set-based subscription (a minimal chain) the collision is invisible; in a composed graph an earlier set-based select poisons the shared key, so a later observe.select(TrackItem.components) silently watches the wrong include set and membership contraction (update(entity, { orderedChildOf: undefined })) never re-emits (before:1, after:1). Every existing test passed an array, so the Set path was unexercised.

Fix

Replace the key builder with a hand-built canonical key:

• include / exclude — sorted (order- and array-vs-Set-agnostic), killing the collision.
• where — keys sorted, values JSON-serialized (so equivalent filters dedup too).
• order — sequence preserved (it's a sort priority).

Chosen over a normalized JSON.stringify (the quick fix) and over a WeakMap identity cache: the hand-built key is ~2.3x faster than stringify in both stable-ref and fresh-literal microbenchmarks and pessimizes neither, on a subscription-setup path where absolute cost is already sub-microsecond. A WeakMap identity cache hits 127 M/s on stable refs but drops to stringify-level on fresh literals — the wrong trade for a cold path.

Tests

New Set-based include block in observe-select-entities.test.ts (red before, green after):

• distinct component Sets return distinct results (direct proof of the collision);
• membership contraction re-emits for a Set-based select even after another set-based select was made (the reported repro).

Full @adobe/data suite (3001 tests) and monorepo typecheck pass.

Related PRs

Follows up #144 (membership-contraction re-emit).