Cross-cutting retrieval and memory enrichment plugin.

Provides in-process memory operations (retrieval.upsert, retrieval.recall, retrieval.clear) plus optional prompt enrichment for chat.message and reasoning.*.run signals.

Enrichment Lifecycle

For enrichable signals, handle_signal/2 runs this lifecycle:

1. Read plugin state (enabled, namespace, top_k, max_snippet_chars).
2. Skip when plugin-level enabled: false.
3. Skip when request payload includes disable_retrieval: true (atom or string key).
4. Extract query text from prompt/query fields.
5. Recall top-k memories from Jido.AI.Retrieval.Store for the active namespace.
6. If memories are found, rewrite payload :prompt with a "Relevant memory" block and attach retrieval metadata under :retrieval.

Signals without a query, and signals with no matching memories, continue unchanged.

Namespace Behavior

mount/2 resolves namespace in this order:

1. Explicit plugin config (:namespace)
2. Agent id (when available)
3. "default"

The resulting namespace is shared by enrichment and retrieval actions unless callers override namespace in action params.

Opt-Out Controls

• enabled: false disables enrichment for all requests on the mounted plugin.
• disable_retrieval: true disables enrichment for one request while keeping retrieval routes available.

Usage

use Jido.AI.Agent,
  name: "retrieval_enabled_assistant",
  plugins: [
    {Jido.AI.Plugins.Retrieval,
     %{
       namespace: "weather_ops",
       top_k: 3,
       max_snippet_chars: 280
     }}
  ]