feat: emergency dispatch to liquidity-monitoring on HIGH/CRITICAL alerts

[spalen0]

Summary

• Adds structured alert system (utils/alert.py) with severity levels (LOW/MEDIUM/HIGH/CRITICAL) and hook support
• Adds utils/dispatch.py that sends repository_dispatch to tapired/liquidity-monitoring when a HIGH or CRITICAL alert fires for a configured protocol
• Migrates infinifi/main.py from raw send_telegram_message to send_alert(Alert(...)) and registers the dispatch hook
• Adds GITHUB_PAT_DISPATCH secret to workflow env
• Per-protocol 60-minute cooldown prevents duplicate dispatches

How it works

1. Infinifi detects liquid reserves < $15M → fires send_alert(Alert(AlertSeverity.HIGH, ...))
2. Alert hook invokes dispatch_emergency_withdrawal
3. GitHub API POST /repos/tapired/liquidity-monitoring/dispatches with {protocol, severity}
4. CRITICAL: liquidity-monitoring zeros caps, commits to main, runs reallocation immediately
5. HIGH: liquidity-monitoring opens a PR with zeroed caps for team review. After merge, manually trigger reallocation.

Companion PR

Receiving side: https://github.com/tapired/liquidity-monitoring/pull/139

Setup required

1. Create fine-grained PAT with actions:write scoped to tapired/liquidity-monitoring
2. Add secret GITHUB_PAT_DISPATCH to this repo

Test plan

• 9 unit tests for dispatch (payload, severity filtering, cooldown, missing PAT, request errors)
• Alert system tests (emoji, severity defaults, hook invocation, exception swallowing)
• Manual end-to-end: gh api repos/tapired/liquidity-monitoring/dispatches -f event_type=emergency_withdrawal -f 'client_payload={"protocol":"infinifi","severity":"HIGH"}'

🤖 Generated with Claude Code

[tapired]

no alerts for alert4 and alert5? Alert4 looks legit to be a "high" too, no?

[spalen0]

no alerts for alert4 and alert5? Alert4 looks legit to be a "high" too, no?

For alert4 and alert5, alert level is set to high: https://github.com/yearn/monitoring-scripts-py/pull/142/changes#diff-82e25bc51cb58224e74ebaac9ac5355b2c0e5bef96527575455fa86e0d849c3bR59