Summary

Adds an SNMP trap provider for Keep (closes #2112).

Because SNMP traps use UDP, the integration bridges them to Keep via HTTP: configure your SNMP trap daemon (snmptrapd, snmptt, or a custom script) to forward trap data as JSON to the Keep webhook URL.

Features

• Webhook-only provider — no credentials required, zero external library dependencies
• SNMPv1 generic trap normalisation — all 7 trap types (0-6) mapped to severity + status
• Explicit severity field — critical/error/warning/info/ok/clear
• Keyword heuristic fallback — scans trapname/description for severity keywords
• Status inference — linkUp/coldStart → RESOLVED; linkDown → FIRING
• Stable fingerprinting — 16-char SHA-1 of source_ip + enterprise + specific_trap for dedup
• Varbind passthrough — all OID-value pairs stored on AlertDto

Changes

Test coverage (55 tests)

• _compute_fingerprint: stability, uniqueness, length
• _severity_from_keywords: 10 patterns + None/empty edge cases
• _parse_severity: explicit field, generic_trap 0-6, keyword fallback
• _parse_status: explicit values, linkUp/linkDown heuristic
• _format_alert: full/minimal/empty payloads, 15+ trap scenarios
• Provider class attributes

/claim #2112