jetstream v2 in zig stream.waow.tech

strata: move the playground source into this repo master

The playground lived untracked in ../strata/archive-spike and was deployed from there by an untracked script. It is now strata/ here, with its own package.json pinning esbuild 0.28.2 and @atcute/lexicons 2.1.0 instead of borrowing the sibling repo's node_modules; `bun run parsers` regenerates the three committed parsers byte-for-byte. `just strata` builds from strata/; a build from the new location produced the same bundle as the live release (889585d25ed94d1c.js). Includes the live avatar fix: spheres and list swatches up to 128 px request Bluesky's avatar_thumbnail instead of the 1000x1000 image, which took Strata's Mobile Safari peak from 700+ MB to about 150 MB and stopped it crashing pages that embed it (release 20260926T045348Z). Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01Ray8ErT7urWdq3aT9Ka87z