Add full-text search, EU channel theme, and web-only sources

Search: new FTS5-backed SearchStories query, /search JSON endpoint,
client-side overlay (search.js) wired into the layout header. EU
channel gets its own theme color (#003399) across bg/text/border/glow
classes. Sources can now route to non-Matrix channels without
validation error (web-only mode); a warning still flags typos.

internal/storage/queries.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"errors"
 	"log/slog"
+	"strings"
 	"time"
 )
 
@@ -347,6 +348,67 @@ func SetRoundRobinState(lastChannel string, tickAt int64) {
 		lastChannel, tickAt)
 }
 
+// SearchStories runs an FTS5 query against headline + lede and returns the
+// best-ranked classified stories (real channels only), newest-ish first via
+// bm25. The user query is tokenized and each token becomes a prefix match;
+// FTS5 special characters are stripped so user input cannot break syntax.
+func SearchStories(query string, limit int) ([]Story, error) {
+	fts := buildFTSQuery(query)
+	if fts == "" {
+		return nil, nil
+	}
+	rows, err := Get().Query(
+		`SELECT s.guid, s.headline, s.lede, s.image_url, s.article_url, s.source, s.platforms, s.channel, s.paywalled, s.seen_at,
+		        EXISTS(SELECT 1 FROM post_log p WHERE p.guid = s.guid) AS posted
+		 FROM stories_fts f
+		 JOIN stories s ON s.id = f.rowid
+		 WHERE f.stories_fts MATCH ?
+		   AND s.classified = 1
+		   AND s.channel IS NOT NULL
+		   AND s.channel NOT IN ('_discarded', '_duplicate')
+		 ORDER BY bm25(stories_fts) ASC, s.seen_at DESC
+		 LIMIT ?`, fts, limit)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var out []Story
+	for rows.Next() {
+		var s Story
+		if err := rows.Scan(&s.GUID, &s.Headline, &s.Lede, &s.ImageURL, &s.ArticleURL, &s.Source, &s.Platforms, &s.Channel, &s.Paywalled, &s.SeenAt, &s.Posted); err != nil {
+			return nil, err
+		}
+		out = append(out, s)
+	}
+	return out, rows.Err()
+}
+
+func buildFTSQuery(raw string) string {
+	var tokens []string
+	var cur strings.Builder
+	flush := func() {
+		if cur.Len() > 0 {
+			tokens = append(tokens, cur.String())
+			cur.Reset()
+		}
+	}
+	for _, r := range raw {
+		switch {
+		case r >= 'a' && r <= 'z', r >= 'A' && r <= 'Z', r >= '0' && r <= '9':
+			cur.WriteRune(r)
+		case r > 127:
+			cur.WriteRune(r)
+		default:
+			flush()
+		}
+	}
+	flush()
+	for i, t := range tokens {
+		tokens[i] = "\"" + t + "\"*"
+	}
+	return strings.Join(tokens, " ")
+}
+
 // MarshalPlatforms converts a string slice to a JSON array string for storage.
 func MarshalPlatforms(platforms []string) string {
 	if len(platforms) == 0 {