lm15 2.0.0 for Rust

The first stable release of lm15 for Rust. The code is 2.0.0-rc.1's, now marked stable: within 2.x the chat core (requests, responses, streaming, tools, structured output, media in messages, reasoning, errors, credentials, model listing) keeps working as documented. Files, batches, media generation, stored caches, realtime sessions, Chat Completions ingest and sign-in stay provisional; see the README's Stability section.

What 2.0 changed from the 1.0 release candidates (a usage counter means one thing on every provider; cost estimates exact or None; major version 2 in every lm15 language): see the 2.0.0-rc.1 notes.

cargo add lm15

Contract cfc3edc: 1,968 of 1,968 checks, like Python 2.0.0, TypeScript 2.0.0, Go v2.0.0, Julia 2.0.0 and R 2.0.0.