v0.3.1

cut hover latency by caching + warming reflection

A hover on a typed variable fanned worse-reflection's reflectOffset out
into many PHP-stdlib reflections with memoization disabled, and the first
stub reflection paid a cold ~512M phpstorm-stubs map build. Hover took
1.6-3.5s and PhpStorm cancelled it before the popup painted (downstream
ticket hover-latency-unindexed-native-symbols). Three fixes:

• Enable worse-reflection's reflection cache on the session reflector,
    collapsing the ~12x same-class reflections a single reflectOffset does.
    The cache is name-keyed with no source version, so ReflectionCachePurger
    flushes it on every didChange; purges land between hovers, preserving the
    intra-hover memoization while an edit always forces re-reflection.
• StubCacheWarmer forces the cold phpstorm-stubs map build off the
    Initialized handshake (async), so the first hover doesn't pay it.
• Variable hover fast-path: a bare $var cursor whose type GenericResolver
    can pin renders directly, skipping reflectOffset. Strictly additive --
    any miss falls through to the unchanged path.

What's Changed

• v0.3.1: cut hover latency by caching + warming reflection by @math3usmartins in #14

Full Changelog: v0.3.0...v0.3.1