[Function Request] NOTTE__RUN_AGENT (extends existing Notte app)

### Required Pre-requisites

- [x] I have read the [Documentation](https://www.aci.dev/docs)
- [x] I have searched the [Issue Tracker](https://github.com/aipotheosis-labs/aci/issues)
- [x] I have searched the [apps directory](https://github.com/aipotheosis-labs/aci/tree/main/backend/apps) to see if this integration already exists

### App Name

Notte (existing app at `backend/apps/notte/`)

### Function Name

NOTTE__RUN_AGENT

### API Docs Link

https://docs.notte.cc/api-reference/agents/agent-create

### Additional Context

The existing Notte integration in ACI (`backend/apps/notte/`) wraps page-level primitives (`START_SESSION`, `OBSERVE_PAGE`, `SCRAPE_DATA`) but doesn't expose Notte's natural-language **agent runtime**, which is the right level of abstraction for many ACI use cases.

`NOTTE__RUN_AGENT` would let an ACI agent delegate a multi-step browsing goal to a Notte agent on hosted infrastructure.

- **Input:** a `task` string, optional `response_format` schema, optional vault credentials, session feature flags (proxies, captcha-solving).
- **Output:** structured response with `.answer`, `.success`, session metadata.

Example task strings:

- "Find the cheapest non-stop SFO→CDG flight on Sep 14 and return the URL"
- "Log in to acme-supplier.com (using vault credentials), download the latest invoice PDF, and return the order total"
- "On linkedin.com, find the email of the CTO at "

**Why this matters for ACI:** many ACI agents today need browser actions but have to either (a) author scripted browser steps with `START_SESSION` + `OBSERVE_PAGE`, or (b) build a meta-agent that drives those primitives. `NOTTE__RUN_AGENT` is the higher-level alternative: pass the goal as natural language and get a structured answer.

The wrapper is a single REST call to Notte's agent endpoint, mirroring the structure of the existing `NOTTE__START_SESSION` wrapper.

**Companion** to the Functions request (`NOTTE__RUN_FUNCTION`) filed alongside this issue: Functions is for repeatable deterministic flows, `RUN_AGENT` is for the exploratory / one-off side.

Happy to PR the wrapper ourselves following ACI's existing patterns in `backend/apps/notte/functions.json`.