feat(autofix): Autofix introspection analytics

[Zylphrex]

This adds an introspection after each autofix step that uses a LLM to judge if we should continue. For now this is behind a feature flag and will only emit analytics as we fine tune this.

[sentry]

Bug: The introspection logic performs a synchronous, 30-second blocking poll within an RPC handler, which can cause worker timeouts and stall the entire autofix pipeline.
_{Severity: HIGH}

Suggested Fix

The introspection logic should be executed asynchronously to avoid blocking the web worker and the main autofix pipeline. Move the call to run_introspection into a background task (e.g., using Sentry's task queue) so that it does not delay or prevent the trigger_autofix_agent call from executing promptly.

Prompt for AI Agent

Review the code at the location below. A potential bug has been identified by an AI
agent. Verify if this is a real issue. If it is, propose a fix; if not, explain why it's
not valid.

Location: src/sentry/seer/autofix/introspection.py#L422-L425

Potential issue: The `run_introspection` function, called from the
`call_on_completion_hook` RPC handler, initiates a synchronous poll for up to 30 seconds
by calling `client.get_run(..., blocking=True, poll_timeout=30)`. This blocks a web
worker for a long duration, risking worker timeouts and process kills. Because this
blocking analytics call occurs before the `trigger_autofix_agent` function is called to
continue the pipeline, a timeout or failure during introspection will prevent the
autofix process from proceeding to the next step. This turns an analytics feature into a
potential blocker for the entire autofix product.

Also affects:

• src/sentry/seer/autofix/on_completion_hook.py:344~352

[Zylphrex]

this is fine for now

[JoshFerge]

makes sense to me! when ready we could add some evals for this as well!