collab-staging: git_ui: Clarify remote-tracking branch delete in branch picker (#61793)

Executive Summary

Closes #56525 Objective Zed's branch picker shows a "Delete Branch" trash icon for both local and remote-tracking branches. For remote-tracking branches (e.g. origin/feature ), this action only deletes the local tracking ref ( git branch -dr ) — it never contacts the remote, and the branch still exists on the actual remote repository. The label gives no indication of this, so users can't tell whether the action is local-only or will delete the branch upstream.

Hyperscale Open Source & Cloud Infrastructure Review

From an infrastructure engineering, cloud-native scale, and hyperscale governance standpoint: - **Hyperscale Provenance:** Open-sourcing internal frameworks subjects proprietary systems to rigorous public analysis. - **De-facto Standard Cohesion:** Publishing enterprise tooling establishes interoperable specifications across distributed execution. - **Vendor Decoupling:** Platform engineers can inspect underlying telemetry and memory layouts without black-box vendor lock-in.

Impact on the Open Ecosystem

Bridges enterprise engineering scale with independent, reproducible open-source software stacks.