feat(cli): webhook notifications for autoresearch events (closes #106)

[Srinivasan8888]

Closes #106.

Motivation

evo optimization loops run autonomously for a long time (SFT/RL cycles are 1–2h+ each, chained across many experiments), but there was no way to be notified when the loop found a new best score. Crawling the evo docs (JS-rendered) and grepping the codebase both confirm no notification/webhook/Slack integration exists anywhere — the public integrations are hosts + remote sandboxes + gates + dashboard. This fills that gap.

What's added

• notify.py — send_notification(url, event, message, extra) POSTs a JSON payload and never raises (a down or misconfigured webhook must not break a run; it returns a bool). The payload sets both text (Slack incoming-webhook key) and content (Discord webhook key) to the message, plus source/event/data, so one URL works for Slack, Discord, or any generic receiver.
• evo config set notify-webhook <url> — stores the webhook (http/https only; empty clears; shown in config show, readable via config get).
• new_best event — at the end of evo run, when a commit beats the previous best (compare_scores(metric, score, best_before_score)), evo fires a best-effort notification:

  🎉 evo: new best score 0.8123 on exp_0007 (previous best 0.7913)

• evo notify test — sends a test notification so users can verify setup without waiting for a run.

Design notes / scope

• Best-effort by design. _maybe_notify and send_notification swallow all errors and only warn on stderr; a failed webhook never affects run outcome.
• In: the notify module, the config field, the new_best event, and evo notify test.
• Out (easy follow-ups): run-finished / budget-cap-hit / experiment-failed events, per-event routing, message templating, retries/backoff.

Tests

tests/unit/test_notify.py (TDD, written failing first) — 11 tests:

• payload carries both text and content + structured data
• send_notification returns True on 2xx, False on non-2xx, and False (no raise) on transport error
• config set notify-webhook stores / rejects non-URLs / clears on empty
• _maybe_notify is a no-op without a webhook and posts when one is set
• evo notify test posts when configured and errors clearly when not

Also verified end-to-end (init → config set notify-webhook → config show → evo notify test fails gracefully against a bogus host, rc=1, no crash). Full tests/unit sweep green.

[devin-ai-integration]

✅ Devin Review: No Issues Found

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