CodeDB v0.2.5859

Hosted semantic retrieval

Fixes codedb context reporting semantic lane: unavailable with the default hosted configuration.

The hosted default model id is now codedb-hosted-v1. Local ANN sidecars built by earlier releases are rebuilt once in the background; the bounded exact rerank serves requests meanwhile. Custom endpoints and explicit model overrides are unchanged.

Local retrieval, the watcher, and the installer are unchanged.