feat(arch): adopt hypermedia & vertical slicing paradigm (Datastar + Deno SSR)
- Establish server-driven hypermedia architecture with Datastar to eliminate brittle imperative client DOM manipulation
- Codify vertical feature slicing (routes, queries, fragments co-located by domain)
- Formalize right-sized dual transport: standard text/html for user mutations, targeted SSE for Valkey pub/sub broadcasts
- Define zero-trust guardrails: untrusted client signals, 16KB payload bounds, rate limiting, and data-ignore subtree protection
- Establish hypermedia error protocol (4xx/5xx return JSX error fragments) and mid-stream SSE resilience
- Add active task checklist with granular 1-to-1 items and shared component suggestions
- Update AGENTS.md with AI-optimized engineering principles (SRP, bounded files, flat call chains, distinctive naming)
Tyler Gillispie
081cd9c765