Upgrade DeepSeek Harness to rc.7

[wisdomqin]

What changed

• pin the 19 direct DeepSeek Harness dependencies to 0.1.0-rc.7
• refresh the lockfile so all 186 Harness prerelease packages resolve consistently to rc.7
• rebase all nine patch-package overlays onto rc.7, preserving DSH Desktop branding, provider onboarding, local file links, Query Rail, directory picking, and Preset import/export
• update Preset package metadata/version mismatch checks and documentation to rc.7
• update the bundled market installer peer dependency and patch-path tests

Why

Harness rc.7 includes upstream fixes for persistent Bash latency, large-history pagination, max-token session preservation, image forwarding, and new plugin/subagent UI capabilities. The desktop patches must be rebased rather than only changing dependency versions because five overlays touched files changed upstream.

Compatibility

• existing local Presets and user data do not require migration
• importing a Preset exported by rc.6 remains allowed and surfaces the existing version-mismatch warning
• the Preset archive format remains version 1

Validation

• npm ci (all nine rc.7 patches applied from a clean install)
• npm test (16 files, 81 tests)
• npm run typecheck
• npm run build
• npm run package:dev:dir (macOS arm64 unpacked development app)
• dsh --version reports 0.1.0-rc.7
• all 186 Harness prerelease packages in the lockfile resolve to rc.7
• patched bundle syntax checks and local node-pty spawn smoke test pass

Remaining release validation

• Windows x64 installer/runtime smoke test, especially the new node-pty beta
• macOS Intel packaging/runtime smoke test
• interactive launch with a copy of an existing rc.6 DSH_HOME before promoting a formal release