0.115.0

chore(release): bump to v0.115.0

- feat(remote): pure drill-down builders for projects and per-project sessions
- feat(remote): bounded-tail recent chat message reader for transcripts
- feat(remote-app): typed drill-down request API with RemoteError
- feat(remote-app): vendor-to-bilko script and desktop command protocol doc
- fix(chat): deliver external send to Epics not yet loaded using payload sessionId/cwd
- feat(remote): drill-down commands for projects, project sessions, session transcript
- feat(remote): replace 5s session-list push with event:remote:ready on E2E auth
- feat(remote-app): ProjectsScreen / SessionsScreen / SessionScreen drill-down
- feat(remote): cmd:chat:send resolves target in main, refuses non-active Epics
- feat(remote): cmd:session:prds returns an Epic's PRD projection
- feat(remote-app): three-level drill-down route, retire SessionNav
- feat(remote-app): event:remote:ready with 20s fallback
- docs(validation): remote drill-down plan review record

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>