Agent A learns a fact, agent B recalls it in a fresh session

[ExtraToast]

Parent

Epic: https://github.com/JorisJonkers-dev/fleet-infra/issues/237

What to build

The headline behaviour: agent A learns a fact, agent B recalls it in a fresh
session with no special reminder.

Wire the installed clients to Hindsight through its native integrations — the
repository ships a .claude-plugin, so this is configuration and
verification, not invention. Inventory the clients and versions actually
installed first; Codex CLI and Hermes are wired only where they really are.

Capture and recall use shared banks per project or domain with agent and
session attribution, not a private bank per transient subagent. Personal,
work and unrelated project scopes stay separate. Bank names and metadata
filters are not authorization boundaries, so authorization is tested at
the service, not inferred from a bank name.

Mere availability of an MCP tool is not automatic memory. If capture depends
on the model choosing to call a tool, say so plainly and use the supported
lifecycle hooks instead.

There is a clean starting point here: the estate's previous knowledge hooks
were removed, so no existing hook competes for ingestion and this becomes
the single owner for agent-session sources.

Acceptance criteria

• A fact stated to one client is recalled by a different client in a new
  session, with no prompt engineering to make it happen.
• Recall is attributed: the answer names the agent, session and time it
  came from.
• A request scoped to one domain cannot read another domain's bank, tested
  at the service.
• The installed clients and versions are recorded, and nothing is
  configured for a client that is not installed.
• Whether capture is automatic or model-elective is stated explicitly for
  each client.
• Existing working client configuration and instructions still function.

Blocked by

• Hindsight deployed: https://github.com/JorisJonkers-dev/fleet-infra/issues/243