Remaining files from the fingerprint-bounties + characterizes-SRO commit:
misp_export, repository, bounties mixin, all 4 router endpoints, and test suite
updates. Prerequisite: previous commit added _extract_fingerprint_bounty_data
and the stix_export changes.
Adds GET /api/v1/attackers/{uuid}/export/misp and
GET /api/v1/attackers/export/misp backed by misp_export.py, which
converts existing STIX bundles to MISP events via misp-stix
ExternalSTIX2toMISPParser. Fleet endpoint emits {response:[...]}
collection (one event per attacker). Frontend: STIX/MISP buttons on
AttackerDetail header and Attackers list. 13 new tests green.