Add zero-content plugin feedback

[mattheliu]

What changed

• add one-click Host-owned plugin health probing with fixed status enums
• add a zero-argument Agent assessment tool that can only return health plus experience=unknown
• require the user to confirm good / mixed / bad before any experience signal exists
• replace the v1 telemetry envelope with a closed zero-content v2 packet
• remove crash monitoring, fingerprints, notes, stable install identity, environment, task, timing and Session-derived metrics
• add a strict v2 PostgreSQL schema, fail-closed backend validation and aggregate-only GitHub reporting
• add a Web probe control, updated result card, privacy contract and migration guidance

Why

The previous implementation minimized and sanitized diagnostic data, but it still handled data derived from Sessions, runtime errors and stable installation identity. The new privacy parameter requires a stronger capability boundary: the health and experience paths must never read logs or content at all.

Operational health and subjective experience are now separate. The Host supplies health; only the user can supply an experience verdict. Network sharing remains a separate explicit action and is described as a zero-content payload rather than anonymous transport.

Compatibility and migration

• package version: 0.3.0
• tested against DeepSeek Harness 0.1.0-rc.6
• old local files and database tables are left untouched but are never read or uploaded by v2
• new installations create only the strict v2 feedback tables

Validation

• pnpm test:all
• 26 Host/Client/privacy tests passed
• 9 backend/HTTP/PostgreSQL tests passed
• real DSH rc.6 package, install, Web boot, Client Loader and remove E2E passed