Add durable interactive cards and BuzzKit notifications

[promptclickrun]

Summary

• Carry validated native cards in assistant Markdown so they survive Direct and Link history, including checklist, selection, and automation card contracts.
• Move managed notifications to account-scoped BuzzKit grants, preserving signed host requests and exact profile/session/turn ownership.
• Carry actual agent response, approval, and clarification content with profile presentation.
• Keep notification delivery failures independent of authoritative work and Live Activity completion.

Hermes hooks -> scoped plugin journal -> authenticated account service -> BuzzKit
assistant message -> validated card fence -> native interactive canvas

Verification

• 49 focused plugin tests passed from this exact distribution checkout in a temporary, credential-free Hermes home.
• Existing form ownership, idempotency, expiry, and managed attention cancellation checks remain covered.
• App-side integration and device delivery are qualified separately in the corresponding internal beta release.
• No credentials, user data, private backend source, or infrastructure configuration is included.

Scope

This PR publishes the plugin source. It does not itself install or restart a running Hermes instance. Physical iPhone notification checks are explicitly delegated to the internal TestFlight tester.