chore: sync model developers data - #2081

…ization, and namespace function tools expansion

Upstream changes merged:
- looplj#2076: Refactored trace-aware strategy from LoadBalanceStrategy into CandidateSelector decorator (TraceStickyMode). Deleted lb_strategy_trace.go in favor of LoadBalancedSelector sticky candidate selection.
- looplj#2073: Normalize empty finish_reason to nil for providers that always emit it.
- looplj#2079: Expand namespace function tools with proper RepresentedToolCount tracking.
- looplj#2081: Sync model developers data.

Conflict resolutions:
- candidates.go: Kept our module path + upstream's contexts import (needed by sticky selection).
- outbound.go CanRetry: Kept both TraceSticky one-shot check (upstream) and EnableSameChannelRetry toggle (ours).
- generated.go: Added TraceStickyMode marshal/unmarshal with our module path; merged fieldsInOrder to include both traceStickyMode and clientRestriction.
- gqlgen.yml: Added TraceStickyMode model mapping with our module path.
- lb_strategy_trace.go/test: Accepted upstream deletion (replaced by decorator pattern).
- request_extensions.go: Took upstream's namespace expansion fix (RepresentedToolCount tracking).
- All looplj module paths replaced with ldm2060.