Summary

Prototype a service-contextual APM service map on the service overview: a focused, hop-limited view of dependencies around the current service, with expand/collapse for hidden neighbors (Option B from Storybook exploration).

Related: observability-dev#5453 / #5428

What changed

Service overview integration

• Adds ServiceOverviewServiceMapSection above the latency chart on /services/{serviceName}/overview.
• Uses existing ServiceMapEmbeddable with enableContextualMap (fetching, loading, popovers stay on the embeddable path).
• Panel chrome: title, “Explore in Service map”, contextual controls (Max visible, Hops, Collapse all), then the map.

Storybook (exploration only)

• Option B stories under service_map/stories/ (service_contextual_map_exploration.stories.tsx, etc.).
• Includes ServiceMapOptionsPanel and filter-aware expand badges for experimentation.
• Filter logic stays in service_contextual_map_expand_utils.ts, separate from production contextual map.