Bump all workspace package versions and APP_VERSION to 2.0.0, marking the
official 2.0 release. Removes the stale 1.x .release-notes.md artifact
(semantic-release regenerates release notes). The 2.0/multimodality docs
and rebrand already landed on main via #254 and #261, so this carries only
the version designation forward from the rebrand branch.
BREAKING CHANGE: SnapOtter 2.0 - the platform re-architecture (Postgres 17 +
Redis 8 + BullMQ durable jobs, 157 tools across five modalities) is the 2.0
release line, replacing the 1.x SQLite single-container architecture.