v0.43.2 — resolve_and_connect

Adds vgi_rpc.launcher.resolve_and_connect(): launches (or reuses) a worker via launcher.launch() and connects via unix_connect(), retrying once on a connect failure that indicates the resolved socket path is stale (the worker self-terminated or died between launch()'s liveness probe and the caller's own connect). Only the connect step is retried — a failure during the RPC session itself always propagates normally.

Mirrors the VGI DuckDB extension's own ResolveAndConnect (vgi_launcher_cache.hpp).