feat(machine-monitor): track Host Monitor on main

[MateoCerquetella]

Summary

• Track the reviewed Host Monitor v0.1.0 source as the third first-class workspace and collection plugin.
• Adapt only main-line development metadata for the private Git-only npm workspace, keeping BB 0.40 / plugin SDK 0.4.21 isolated from the existing BB 0.38 plugins.
• Add the public README, sanitized screenshots, collection install paths, third-party notices, lockfile graph, and durable Empirical verification records.
• Preserve the released product source byte-for-byte outside the explicit README/package/test-loader adaptation allowlist.

UI

Processes and floating monitor

Verification

• npm install — 0 vulnerabilities.
• npm run check --workspace bb-plugin-machine-monitor — SDK check, typecheck, 144/144 tests, server/app/host build.
• npm run check — all three workspaces pass.
• Artifact metadata — server/app/host all BB 0.40.0 and SDK 0.4.21.
• Live local-path BB walkthrough — cards, rows, masked-IP inspector, searchable/sortable process ledger, sidebar outside-click dismissal, and keyboard-movable floating monitor.
• Independent security, privacy/package, UI, and final code review — no remaining blocker.
• Independent clean-worktree capability replay and root verification — pass.
• git diff --check — pass.

Release invariants

• machine-monitor/v0.1.0 still peels to 9db09cc35553493113f31e5352a44911ae92bc73.
• Marketplace PR #128 remains open and unchanged by this PR.
• No npm publication and no unrelated navigation changes.

Ready for review; this PR has not been merged.