Merge master 62b700bba7bb71e66d2d5a3b850ba8f4dd0fd6b4 into release/session-log-v4 at 4825bc01a999f564e79172a6af28e34fc757c540. Preserve this pinned integration checkpoint before any later upstream movement so the dependent session-format repairs have an immutable rebase base.
Keep release projection-backed child catalogs, independent Session references, exact fork behavior, V4 writer, and existing migration data. Adapt the incoming subagent sidebar chat to refreshProjections rather than the removed dedicated catalog API, preserve title projections in complete projection fixtures, and retain both sidebar actions and release lineage/status behavior. Remove the duplicate SessionProjectionMap import introduced by automatic merging.
Preserve both disjoint archive seals without changing any existing hash. Regenerate current Cordis and documentation catalogs from the combined source, retaining release session methods plus master slot factories. The frozen V0-V3 runtime paths are unchanged. Initial validation passed the full build, 93 focused Client tests, and all 1905 archived artifact seals; remaining integration and snapshot checks follow on this checkpoint.