Add remember forget and inspect UX for agent memory

[michaelmwu]

Parent: #265

Goal

Add user/admin UX for remembering, inspecting, and forgetting durable memory facts.

Scope

• Add memory_write.remember_fact behind confirmation/admin policy.
• Add memory_write.forget_fact behind user/admin policy.
• Add inspect/list behavior for:
  • "what do you remember about me?"
  • project memory facts
  • org/admin-visible memory facts
• Require confirmation before persisting inferred facts.
• Show provenance when displaying memory.

Example UX

I can remember that you prefer GitHub issues over Linear for this repo.
Reply `confirm` to save this preference.

Remembered facts:
- timezone: Asia/Taipei
  source: confirmed by you on 2026-05-08

Acceptance criteria

• Users can inspect their own durable memory.
• Users/admins can delete facts they are allowed to manage.
• Inferred facts are not persisted without confirmation.
• Memory displays include source/provenance.
• Tests cover confirmation, denied deletes, and display redaction.