DummyConnector: declarative scriptable rule engine

[AimTune]

DummyConnector currently has hard-coded demo paths (/genui-weather, /genui-form, etc.). Make those declarative so the sandbox — and any third party using DummyConnector for demos / e2e tests — can configure response behavior without forking the connector.

Motivation

• Backend-less demos. "When the user says 'cancel', show this card with two buttons."
• E2E test fixtures. Replay deterministic conversations without spinning up a real bot.
• Customer presentations. Show a tailored flow before the real backend exists.
• Pairs naturally with the sandbox's ChativaSettings JSON paste-load: rule sets travel as part of the same config blob.

Proposed shape (v1)

type DummyRule = {
  /** Predicate over the user's outgoing message. */
  when: {
    type?: string;                         // match by message type
    textMatches?: string;                  // regex string applied to data.text
  };
  /** Static response, OR a GenUI chunk script. */
  then:
    | IncomingMessage
    | { kind: "genui"; chunks: AIChunk[] };
  /** Optional delay before emitting `then`. Defaults to `replyDelay`. */
  delay?: number;
};

new DummyConnector({
  replyDelay: 500,
  rules: [
    {
      when: { textMatches: "^/(help|yardım)$" },
      then: { id: "x", type: "buttons", from: "bot", data: { buttons: [{ label: "Order status" }, { label: "Talk to a human" }] } },
    },
    {
      when: { textMatches: "(cancel|iptal)" },
      then: { kind: "genui", chunks: [/* text + form */] },
    },
  ],
});

Rules evaluated in order; first match wins. No match → fall through to the default echo.

Hard rules

• No custom JS execution. Pattern matching only — textMatches is a regex string, not arbitrary code.
• All rule output passes through the existing IncomingMessage / AIChunk types (no new schemas needed besides updating connector option schema).

Sandbox integration

A new "Rules" tab in apps/sandbox/src/sandbox/sections/:

• Add / edit / remove rules in a list.
• "Apply" rebuilds the DummyConnector instance via the existing Connector tab swap path.
• Rules serialise into the Config tab's JSON output as a dummy.rules field of chativaSettings.connector.

Schema impact

Update schemas/connectors/dummy.schema.json to include the rules field. Add a drift test for it (also covered by #4 / schema-coverage).

Acceptance criteria

• DummyConnector accepts rules in its constructor options.
• Rules with textMatches regex match outgoing messages and emit the configured then.
• GenUI rules emit chunks via genUIChunkHandler.
• Existing demo helpers (triggerGenUI, injectMessage) keep working.
• Sandbox UI to add / edit / remove rules.
• connector-dummy tests for rule matching, ordering, and fall-through.
• schemas/connectors/dummy.schema.json updated and drift-tested.

---

Spun out of todos.md.