adventure: publish gogobee's LLM prose, guarded, template as the net

gogobee's LLM now authors a dispatch's headline and lede; Pete prefers them
over its template render when both are present and pass a prose-level guard,
and falls back to the template otherwise. factGuard only ever checked the
structured Subject/Opponent fields, which was the whole safety story while a
Pete template was the renderer — a template prints nothing Pete did not
interpolate. LLM prose breaks that: the guard would be validating fields that
are no longer what's rendered. proseGuard checks the rendered text itself,
rejecting a known adventurer named outside the fact's Actors (a live way to
put words in a real player's mouth) and anything past the length caps. The
templates stop being the renderer and become the safety net; they are not
deleted.

internal/storage/roster.go

@@ -4,6 +4,7 @@ import (
 	"database/sql"
 	"encoding/json"
 	"log/slog"
+	"strings"
 )
 
 // RosterEntry is one adventurer's currently-true state, as of the last snapshot
@@ -140,3 +141,31 @@ func RosterSnapshotAt() int64 {
 	}
 	return at.Int64
 }
+
+// KnownCharacterNames returns the set of character names on the current board,
+// lowercased, for the prose-guard. It is the answer to "is this a name of a real
+// adventurer other than the one the fact is about" — a name Pete knows but that
+// the fact did not authorize walking onto a public page.
+//
+// Best-effort: an empty set (query error, or gogobee has never pushed a board)
+// disables only the name half of the guard, never the length caps. The board is
+// a snapshot, so a character who has dropped off it is not covered — the guard's
+// job is protecting people who are currently in the realm, not auditing history.
+func KnownCharacterNames() map[string]bool {
+	rows, err := Get().Query(`SELECT name FROM adventure_roster WHERE name <> ''`)
+	if err != nil {
+		slog.Error("KnownCharacterNames query failed", "err", err)
+		return nil
+	}
+	defer rows.Close()
+
+	names := make(map[string]bool)
+	for rows.Next() {
+		var name string
+		if err := rows.Scan(&name); err != nil {
+			continue
+		}
+		names[strings.ToLower(name)] = true
+	}
+	return names
+}