Announced pages: event windows, header announcements, summary tasks

A question may carry event: {starts, duration, place}. While the
window is open the page is announced in a strip at the top of every
header (name, when, 'in 3 days'), soonest first, and kept out of the
footer nav; when it closes the page becomes a followup - only a
visitor carrying an answer chain still sees it.

announce.rs keeps one record per event page in the runtime-owned
portal_events bucket (built-in state graph: announced ->
awaiting_summary -> summarized, content may override) and, on a
one-minute idempotent sweep, moves ended windows to awaiting_summary,
publishing the transition on portal.answers.submitted as 'Summary
due' - the post-what-happened task a review desk picks up. Lint
warns when event pages exist but nothing reads portal_events.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/announce.rs

@@ -0,0 +1,147 @@
+//! Announced pages (`Question.event`): keeps one `portal_events` record
+//! per event question and, once a window closes, moves it to
+//! `awaiting_summary` - the "post what happened" task - publishing the
+//! transition on `portal.answers.submitted` like any desk decision, so
+//! the desktop notifier and n8n hear it. Runs on a one-minute tick;
+//! every step is idempotent, so a restart or a content reload in the
+//! middle changes nothing.
+
+use crate::answers::{store_answer, Answer};
+use crate::content::EVENTS_BUCKET;
+use crate::events::{emit_answer_submitted, AnswerSubmitted};
+use crate::server::AppState;
+
+/// Alternative name stamped on the auto-created record and on the
+/// transition event - what an n8n workflow gates on.
+pub const EVENT_ALTERNATIVE: &str = "Announced";
+pub const SUMMARY_DUE_LABEL: &str = "Summary due";
+
+/// Record id for an event question: its id with `/` folded to `-`
+/// (`/events/opening` -> `events-opening`), so one page is one record
+/// however many times the sweeper runs.
+pub fn record_id(question_id: &str) -> String {
+    question_id.trim_matches('/').replace('/', "-")
+}
+
+pub async fn run(state: AppState) {
+    let mut tick = tokio::time::interval(std::time::Duration::from_secs(60));
+    loop {
+        tick.tick().await;
+        if let Err(e) = sweep(&state).await {
+            tracing::warn!(error = %e, "event sweep failed");
+        }
+    }
+}
+
+/// One pass: create missing records, close ended windows.
+pub async fn sweep(state: &AppState) -> anyhow::Result<()> {
+    let now_ms = chrono::Utc::now().timestamp_millis();
+    let questions = state.questions.load();
+    let events: Vec<_> = questions.values().filter(|q| q.event.is_some()).cloned().collect();
+    if events.is_empty() {
+        return Ok(());
+    }
+    let aggregates = state.aggregates.load();
+    let schema = aggregates
+        .get(EVENTS_BUCKET)
+        .ok_or_else(|| anyhow::anyhow!("no {EVENTS_BUCKET} schema"))?;
+    let store = match state.jetstream.get_key_value(EVENTS_BUCKET).await {
+        Ok(store) => Some(store),
+        Err(_) => None,
+    };
+
+    for q in events {
+        let event = q.event.as_ref().expect("filtered");
+        let (starts, ends) = match event.window_ms() {
+            Ok(w) => w,
+            Err(_) => continue, // validated on load; belt and braces
+        };
+        let id = record_id(&q.id);
+        let existing: Option<Answer> = match &store {
+            Some(store) => store
+                .get(&id)
+                .await?
+                .and_then(|bytes| serde_json::from_slice(&bytes).ok()),
+            None => None,
+        };
+        let responses = serde_json::json!({
+            "name": q.name,
+            "starts": event.starts,
+            "starts_ms": starts,
+            "ends_ms": ends,
+            "place": event.place,
+            "page": q.id,
+        });
+
+        let answer = match existing {
+            None => {
+                store_answer(
+                    &state.jetstream,
+                    &aggregates,
+                    EVENTS_BUCKET,
+                    id.clone(),
+                    &q.id,
+                    EVENT_ALTERNATIVE,
+                    &responses,
+                    now_ms,
+                )
+                .await?;
+                tracing::info!(question = %q.id, "event record created");
+                continue;
+            }
+            Some(a) => a,
+        };
+
+        if answer.state == schema.initial && now_ms >= ends {
+            let target = "awaiting_summary";
+            let payload = serde_json::json!({ "to": target, "item": id, "by": "portal" });
+            match crate::aggregates::transition(&state.jetstream, schema, &id, target, payload.clone(), now_ms).await {
+                Ok(_) => {}
+                Err(crate::aggregates::TransitionError::UnknownAggregate) => {
+                    crate::aggregates::reseed(&state.jetstream, schema, &id, &answer.state, now_ms)
+                        .await
+                        .map_err(|e| anyhow::anyhow!("{e}"))?;
+                    crate::aggregates::transition(&state.jetstream, schema, &id, target, payload.clone(), now_ms)
+                        .await
+                        .map_err(|e| anyhow::anyhow!("{e}"))?;
+                }
+                Err(e) => return Err(anyhow::anyhow!("{e}")),
+            }
+            let mut answer = answer;
+            answer.state = target.to_string();
+            answer.decided_ms = Some(now_ms);
+            answer.decided_by = Some("portal".to_string());
+            let store = state.jetstream.get_key_value(EVENTS_BUCKET).await?;
+            store.put(&id, serde_json::to_vec(&answer)?.into()).await?;
+
+            let parent_hashes = vec![id.clone()];
+            let chain_hash = crate::chain::hash_node(&q.id, &parent_hashes, &payload, now_ms);
+            emit_answer_submitted(
+                &state.nats,
+                &AnswerSubmitted {
+                    chain_hash,
+                    parent_hashes,
+                    question_id: q.id.clone(),
+                    alternative: SUMMARY_DUE_LABEL.to_string(),
+                    responses: payload,
+                    timestamp_ms: now_ms,
+                },
+            )
+            .await?;
+            tracing::info!(question = %q.id, "event ended - summary due");
+        }
+    }
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::record_id;
+
+    #[test]
+    fn record_id_is_stable_and_flat() {
+        assert_eq!(record_id("/events/opening"), "events-opening");
+        assert_eq!(record_id("/"), "");
+        assert_eq!(record_id("/opening"), "opening");
+    }
+}