Add editable private feedback summaries

[mattheliu]

What changed

• replace structured live-recomputed editing with one direct, bounded Summary textarea
• add schema v4 while preserving schema v3 backend and local-history compatibility
• reject common pasted log, path, URL, email, credential, and stack shapes on both client and server
• keep each Summary private to the feedback backend and exclude it from clustering and GitHub aggregate Issues
• add PostgreSQL migration, protocol tests, component tests, service tests, and real rc.6 lifecycle coverage

Why

The previous editor made a tiny feedback action feel like a configuration form. This keeps the default deterministic summary, but lets the user directly rewrite the exact sentence they will send without any live recomputation.

Privacy impact

The plugin still never automatically reads Session text, logs, exceptions, files, or local paths. The one free-text field is user-entered, limited to 320 characters, previewed before every send, and protected by fail-closed shape guards. The documentation now explicitly says these guards are not a complete anonymizer.

Validation

• pnpm test:all
• 38 client/core tests
• 11 server tests
• real DeepSeek Harness rc.6 pack/install/Host/Web/client-loader/uninstall lifecycle
• local UI flow: edit, reject path, apply safe Summary, confirm, queue during outage, and automatic retry to received