Phase 1: complete canonical service registry

[kacy]

Summary

• add the in-memory service registry state machine and runtime wrapper backed by the durable services / service_endpoints tables
• wire the existing service registry bridge into that runtime so shadow state stays synchronized with persisted service membership and probe transitions
• add /v1/services routes for listing services, inspecting endpoints, requesting reconcile, draining endpoints, and removing endpoints
• round out the registry model with node-loss / node-recovery and reconcile success / failure state so Phase 1 is complete before the reconciler lands

Commits

• cf48b8e Add service registry runtime state machine
• 2bab36b Add service registry API routes

Verification

• env YOQ_SKIP_SLOW_TESTS=1 ZIG_GLOBAL_CACHE_DIR=.zig-global-cache ZIG_LOCAL_CACHE_DIR=.zig-local-cache timeout 30 zig build test -- --test-filter "replaceServiceEndpoints preserves observed health for matching endpoint ids|runtime bootstraps from persisted services|runtime sync preserves probe health across persisted refresh|container bridge preserves legacy DNS and shadow events|bridge can skip shadow record while preserving legacy apply" timed out after 30s with no emitted failures
• env YOQ_SKIP_SLOW_TESTS=1 ZIG_GLOBAL_CACHE_DIR=.zig-global-cache ZIG_LOCAL_CACHE_DIR=.zig-local-cache timeout 30 zig build test -- --test-filter "route handles GET /v1/services|route handles GET /v1/services/{name}|route handles GET /v1/services/{name}/endpoints|route handles POST drain and DELETE endpoint|route handles POST /v1/services/{name}/reconcile|dispatch services routing|runtime bootstraps from persisted services|runtime sync preserves probe health across persisted refresh" timed out after 30s with no emitted failures
• env YOQ_SKIP_SLOW_TESTS=1 ZIG_GLOBAL_CACHE_DIR=.zig-global-cache ZIG_LOCAL_CACHE_DIR=.zig-local-cache timeout 30 zig build test -- --test-filter "node loss and recovery toggle endpoint eligibility|markReconcileFailed and markReconcileSucceeded update service detail|runtime can mark reconcile failure and recovery|route handles GET /v1/services|route handles POST drain and DELETE endpoint|dispatch services routing" timed out after 30s with no emitted failures

Follow-up

• Phase 2 can now move DNS/LB programming behind the deterministic reconciler instead of using the bridge as the shadow event source
• the bridge still persists :0 endpoint identities until node / port identity is threaded through the runtime callers