feat(champ): stream champion-spawn state to the sidecar board

Champion spawns have no ServUO EventSink, so add a fourth polled stream
(BridgeChamps) modeled on BridgeSweeps: enumerate every spawn each tick,
fold to a small record, and emit champ.update only on change. No core
patch — every field used is public.

Covers all three families via a `category` field:
  - champion: ChampionSpawn (type/level/kills/boss/cooldown ETA)
  - mini:     MiniChamp (type/level; auto-restarts, no kill counter)
  - sea:      BaseSeaChampion (a High Seas world-boss mobile, alive only
              while summoned; removed via champ.remove when slain)

Status folds to active/cooldown/dormant. A (re)connection clears the diff
cache so the next sweep re-emits the full board, rebuilding a sidecar that
restarted on its own. Transient entries leave via champ.remove.

Sidecar: a `champs` current-state table (one row per serial) fed by
champ.update (upsert) and champ.remove (delete), exposed at GET /champs as
the live board. New ChampSweepSeconds config (default 10s), wired into
[bridge reload/sweepnow/status. Documented in docs/INTEGRATION.md.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0114TpmrNW4wNXsHq5CR72jQ

sidecar/src/store.rs

@@ -133,6 +133,50 @@ impl Store {
             .await?;
         Ok(row.and_then(|r| serde_json::from_str(&r.get::<String, _>("json")).ok()))
     }
+
+    /// Upserts one champion-spawn's latest state, keyed by serial. Fed from the `champ.update`
+    /// stream; this table is the live board the website reads, so there is exactly one row per
+    /// spawn and it always holds the most recent snapshot.
+    pub async fn upsert_champ(
+        &self,
+        serial: &str,
+        status: Option<&str>,
+        name: Option<&str>,
+        json: &str,
+        t: i64,
+    ) -> anyhow::Result<()> {
+        sqlx::query(
+            "INSERT INTO champs (serial, status, name, json, updated_t) VALUES (?, ?, ?, ?, ?)
+             ON CONFLICT(serial) DO UPDATE SET status = excluded.status, name = excluded.name, json = excluded.json, updated_t = excluded.updated_t",
+        )
+        .bind(serial)
+        .bind(status)
+        .bind(name)
+        .bind(json)
+        .bind(t)
+        .execute(&self.pool)
+        .await?;
+        Ok(())
+    }
+
+    /// Drops one spawn from the board. Fed from the `champ.remove` stream: a controller that was
+    /// deleted, or a transient sea boss that was slain, leaves the board this way.
+    pub async fn delete_champ(&self, serial: &str) -> anyhow::Result<()> {
+        sqlx::query("DELETE FROM champs WHERE serial = ?")
+            .bind(serial)
+            .execute(&self.pool)
+            .await?;
+        Ok(())
+    }
+
+    /// The full champion-spawn board: every spawn's latest snapshot. Ordered by name so the site
+    /// gets a stable list.
+    pub async fn champs_all(&self) -> anyhow::Result<Vec<Value>> {
+        let rows = sqlx::query("SELECT json FROM champs ORDER BY name, serial")
+            .fetch_all(&self.pool)
+            .await?;
+        Ok(parse_json_column(rows))
+    }
 }
 
 fn parse_json_column(rows: Vec<sqlx::sqlite::SqliteRow>) -> Vec<Value> {
@@ -163,4 +207,12 @@ CREATE TABLE IF NOT EXISTS profiles (
     json      TEXT NOT NULL,
     updated_t INTEGER NOT NULL
 );
+
+CREATE TABLE IF NOT EXISTS champs (
+    serial    TEXT PRIMARY KEY,
+    status    TEXT,
+    name      TEXT,
+    json      TEXT NOT NULL,
+    updated_t INTEGER NOT NULL
+);
 "#;