Add 26.2 to proportionalLiquidGravity

[DallasCarraher]

Summary

Physics() throws No liquid gravity settings, have you made sure the liquid gravity features are up to date? for any version whose majorVersion matches neither independentLiquidGravity nor proportionalLiquidGravity in lib/features.json. 26.2 was missing from the latter (last entry was 26.1), breaking Physics() construction for every consumer — mineflayer's pathfinder plugin included — as soon as minecraft-data ships data for 26.2.

Not actually 26.2-specific in cause: this reproduces today on 26.1 too if you swap in a minecraft-data build that's missing the feature entry, since this list has to be manually kept in sync with every new major release regardless of what data is available. 26.2 is just the version that surfaced it.

Found while live-testing PrismarineJS/minecraft-data#1298 (26.2 data) against mineflayer's pathfinder plugin — bot spawned fine, but Physics() construction failed at plugin-injection time until this was patched locally.

Related:

• PrismarineJS/minecraft-data#1298 — 26.2 data
• PrismarineJS/prismarine-chunk#333 — 26.2 chunk implementation mapping
• This PR
• PrismarineJS/node-minecraft-protocol#1529 — login success packet sessionId
• PrismarineJS/mineflayer#4121 — 26.2 added to testedVersions

Test plan

• Added test/liquidGravity.test.js regression test covering this specific gap
• Full suite passes (20/20) against minecraft-data#1298's branch
• standard lint clean

[rom1504]

Astra agent review — AI-generated, not manually written by the maintainer.

Rechecked 7d697da and the existing discussion.

This overlaps #145's gravity-feature extension; #145 also includes 26.3 and a regression assertion. I recommend landing the broader focused version and then closing/consolidating this duplicate once its 26.2 entry is preserved. This PR has no independent movement implementation that needs a separate landing.

This is a static overlap assessment, not a new full-version physics validation.

Skills used: prismarine-geometry-movement-review checked the changed geometry or simulation scope; prismarine-protocol-data-review checked version selection and candidate-versus-release readiness; prismarine-review checked current scope and existing feedback to avoid duplicate threads.

[DallasCarraher]

Thanks for the review. Agreed that #145 is the broader version (26.2 + 26.3, with a regression assertion) and this PR has no independent change, so #145 is the one to land. The 26.2 entry is preserved there. I'll leave this open until #145 is merged, then close it as a duplicate unless a maintainer prefers otherwise.