Establish v4 package identities and versions
Merged
MO
3mo ago+200+200+012345678901234567890123456789-44-44-01234567890123456789
The v4 spike used temporary package names and versions. This PR establishes the package identities and version numbers we want to carry into production.
The public TypeScript and Python SDKs both start at 4.0.0. The new protocol package starts at 1.0.0, and its major version is used for the compatibility handshake between the SDK and extension. The docs, protocol, server, and Python version-tracking package remain private.
This PR also adds the small .env.example required by v4 and makes package metadata the source of truth for runtime version reporting.
There is no publishing automation in this PR. It only establishes the package names, versions, and metadata that the release flow in the next PR will use.