v1.1.48-open-runtime-fork.6

fix: extract base semver for plugin version matching

Handles custom fork version strings like "1.1.48-open-runtime-fork.5"
by extracting the base semver "1.1.48" for @opencode-ai/plugin installation.

This allows the fork to use the official @opencode-ai/plugin package
from npm without requiring a separately published fork plugin.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>