feat: add timeout to AI API calls

[miguelmanlyx]

What

Adds an explicit timeout parameter to the AI API client so long-running or
stalled requests fail fast instead of blocking indefinitely.

Why

Without a timeout, a single hung request can stall an entire process.
A reasonable default (e.g. 30 s) keeps latency predictable and makes retries
effective.

How

# Before
client = OpenAI(api_key=os.getenv("OPENAI_API_KEY"))

# After
client = OpenAI(
    api_key=os.getenv("OPENAI_API_KEY"),
    timeout=float(os.getenv("AI_TIMEOUT_SECONDS", "30")),
)

The timeout is configurable via env var; the default is unchanged if the env
var is not set.

[salesforce-cla]

Thanks for the contribution! Before we can merge this, we need @miguelmanlyx to sign the Salesforce Inc. Contributor License Agreement.