Auto-review follow-ups for PR #207: feat(server): let a request name the tab that relays it

[github-actions]

Tracking auto-review follow-ups for #207 (verdict: pass).

🟡 Nits

• --via-tab is not validated at the CLI layer like the request URL is, so malformed/off-domain values surface as exit 2 (bridge error) instead of exit 1 (usage error)

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When addressing the review on #207, resolve each item and add Closes #<this issue> to the PR once everything is genuinely fixed; deferred items stay open here. See the auto-review follow-up convention in CLAUDE.md.