Add CapabilityAwareRoutingStrategy — it hard-filters to providers that declare every
required capability (like FirstAvailable) but ranks the matches by summed required-capability
score; ties keep list order, so it is a strict superset of first-available. The server now
wires it as the routing policy.
The orchestrator augments a stage's required capabilities with ModelCapability.ToolCalling
when the stage grants tools, so tool-heavy stages route to the best tool-calling model rather
than whichever healthy provider comes first.
Scores come from each provider's declared capabilities(); observed per-model reliability
(GET /metrics/tool-reliability) can feed in later as an additional weight.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
kami
82674e85c4