Fixes agent routing for browser-uploaded attachments.
- Binds each draft attachment to the exact accepted user turn and leaves a visible attachment receipt in conversation history.
- Gives every selection a unique attachment_id, including same-name and byte-identical files, while reusing immutable CAS bytes.
- Adds read_attachment as the default model entry and blocks filesystem guessing for uploaded attachments.
- Recovers partial Finder multi-file drops, adds an RPC version handshake, and raises the per-session total to 1 GiB.
- Ships the official dsh.bundle install path alongside the external dshx development path.
Verified with a public-data audit, 38 tests, a clean build, isolated offline package reinstall, OfficeCLI 1.0.144 hash/version checks, and a real two-same-name-file DSH model flow.
TGZ SHA-256: 9c32b79ea059fd32455460e031489bc43d3540c23d9542f166edfad839f82b37