feat: add x-sfc-client header hook

[andreaanez]

Summary

• Adds ClientHeaderHook (in internal/hooks/client_header.go) that sets x-sfc-client: speakeasy/go-{version} on every request. Version is parsed from SDKConfiguration.UserAgent at SDKInit time so it stays in sync with the generated SDK version.
• Adds internal/hooks/registration.go with initHooks(h) registering the new hook for both SDKInit and BeforeRequest chains.
• Patches internal/hooks/hooks.go New() to call initHooks(h). Speakeasy's regen would emit this same call automatically given the presence of registration.go, but speakeasy run -y is currently blocked by an unrelated spec lint error (duplicate Orders tag in openapi.json), so the call is added manually for now.

Lets server-side middleware identify the SDK explicitly via x-sfc-client instead of parsing the speakeasy-generated User-Agent, whose format Speakeasy can change.

Test plan

• go build ./... passes
• go test ./internal/hooks/... — TestClientHeaderHook covers speakeasy UA, empty UA, and single-token UA → all pass
• End-to-end via httptest server: confirmed receiving x-sfc-client: speakeasy/go-0.0.1
• Reviewer: confirm header value format speakeasy/go-{version} matches what server-side middleware expects

Follow-up

Spec has a duplicate Orders tag (openapi.json lines 8448 and 8496) blocking speakeasy run. Fix upstream in the blueprint repo by giving the order-estimation tag a distinct name (e.g. Order Estimates).

🤖 Generated with Claude Code

[semanticdiff-com]

Review changes with  

Changed Files

File	Status
internal/hooks/client_header.go	0% smaller
internal/hooks/client_header_test.go	0% smaller
internal/hooks/hooks.go	0% smaller
internal/hooks/registration.go	0% smaller