[codex] Prepare public profile README

[amitkot]

Summary

Updates the repository README so the project reads cleanly as a public portfolio project for local-first developer tooling and coding-agent workflows.

Changes include:

• Reworked the top of the README with positioning, status, highlights, and architecture.
• Added concrete example use cases for humans, agents, hooks, GitHub webhooks, and SSE.
• Added dashboard, task detail, chronological stream, and lane stream screenshots under docs/screenshots/.

Validation

• git diff --cached --check
• pre-commit hooks during commit:
  • trailing whitespace
  • end-of-file fixer
  • large-file check
  • private-key detection
  • hardcoded-secret detection
  • cargo fmt/clippy hooks skipped because no Rust files changed

No runtime tests were run because this is documentation and screenshot-only.