docs(readme): swap hero GIF to the live dashboard view

[vaderyang]

What

Swap the README hero from the pcap-replay demo to the live dashboard GIF
(total calls, TTFT, E2E latency, error rate, token throughput, call volume,
latency percentiles, and agent activity/distribution).

• docs/images/hero.gif replaced (1280×720, animated)
• alt-text updated to describe the dashboard
• caption updated — dropped the stale "247 calls → 12 agent turns" line that no
  longer matched the image

The hero.gif filename is reused (README src unchanged), and the pcap
quick-start narrative + blockquote are kept (product's core flow is unchanged).

Docs-only — no binary or version impact.

[github-actions]

Summary

PR #178 is a docs-only change that swaps the hero GIF in README.md for a live-dashboard recording and updates the surrounding alt-text/caption to describe the dashboard's actual contents (TTFT, latency, throughput, error rate, per-agent mix) rather than the old "247 calls → 12 agent turns" narrative. The src path is unchanged so no link breakage, the new alt-text lists only generic metric category names (no values, IPs, credentials, hostnames, or paths), and the commit message accurately matches the diff. APPROVE.

Verified

• README.md:18 — new alt text reads as a description of the live dashboard view; no sensitive values, only metric category names (TTFT, E2E latency, error rate, token throughput, call volume by API, latency percentiles, agent activity/distribution).
• README.md:18 — src="docs/images/hero.gif" unchanged; path is stable, so no broken image link elsewhere in the repo.
• README.md:22 — caption rewritten to match the new image; old "247 calls → 12 agent turns" phrasing dropped, consistent with the commit message claim.
• Surrounding quick-start narrative (install one-liner, --pcap-file / --no-retention replay, #30-second-quick-start anchor link) is untouched — the anchor target still exists at README.md:27.
• docs/images/hero.gif binary swap (70 KB → 352 KB) is consistent with replacing a short demo clip with a longer live-dashboard recording; no path change.
• No Rust, SQL, schema, console, or config files touched — schema-drift, body-scan, stale-queryKey, capture-pipeline, and mode-switch checks are all not applicable by construction.
• Sensitive-information scan of the two text lines: no private IPs, no credentials/keys, no internal hostnames or machine paths, no team/app identifiers. The numbers "247" and "12" are removed, not added.
• Commit message (docs(readme): swap hero GIF to the live dashboard view) matches the diff exactly — no scope drift between commit claim and actual changes.

---

🤖 Reviewed by the review bot • workflow run