fix(suggestions): enable combined search, progressive BPM widening, and include db in docker build

server/db.js

@@ -188,7 +188,10 @@ async function searchTracks(queryStr, limit = 10) {
       const res = await getPool().query(
         `SELECT id, title, artist, camelot_key, bpm, music_key, cover_url, is_corrected
          FROM tracks
-         WHERE LOWER(title) LIKE $1 OR LOWER(artist) LIKE $1
+         WHERE LOWER(title) LIKE $1 
+            OR LOWER(artist) LIKE $1
+            OR LOWER(artist || ' ' || title) LIKE $1
+            OR LOWER(title || ' ' || artist) LIKE $1
          ORDER BY is_corrected DESC, play_count DESC
          LIMIT $2`,
         [term, limit]
@@ -202,7 +205,9 @@ async function searchTracks(queryStr, limit = 10) {
   const results = [];
   const q = queryStr.toLowerCase();
   for (const track of memoryTracks.values()) {
-    if (track.title.toLowerCase().includes(q) || track.artist.toLowerCase().includes(q)) {
+    const combined1 = `${track.artist} ${track.title}`.toLowerCase();
+    const combined2 = `${track.title} ${track.artist}`.toLowerCase();
+    if (track.title.toLowerCase().includes(q) || track.artist.toLowerCase().includes(q) || combined1.includes(q) || combined2.includes(q)) {
       results.push(track);
       if (results.length >= limit) break;
     }

server/routes/suggestions.js

@@ -26,13 +26,25 @@ router.get('/', async (req, res) => {
     // 1. Fetch tracks from PostgreSQL within ±6%
     let tracks = await db.getSuggestions(compatibleKeys, minBpm, maxBpm, 10, artist, title);
 
-    // 2. If fewer than 8 tracks, widen BPM range to ±12% to guarantee plenty of suggestions
+    // 2. If fewer than 8 tracks, widen BPM range to ±12%
     if (tracks.length < 8) {
       minBpm = Math.round(currentBpm * 0.88);
       maxBpm = Math.round(currentBpm * 1.12);
       tracks = await db.getSuggestions(compatibleKeys, minBpm, maxBpm, 10, artist, title);
     }
 
+    // 3. If fewer than 5 tracks, widen BPM range to ±20% for smaller libraries
+    if (tracks.length < 5) {
+      minBpm = Math.round(currentBpm * 0.80);
+      maxBpm = Math.round(currentBpm * 1.20);
+      tracks = await db.getSuggestions(compatibleKeys, minBpm, maxBpm, 10, artist, title);
+    }
+
+    // 4. If still empty, fetch any compatible key track (50-220 BPM)
+    if (tracks.length === 0) {
+      tracks = await db.getSuggestions(compatibleKeys, 50, 220, 10, artist, title);
+    }
+
     // 3. Map tracks with compatibility info and colors
     const enriched = tracks.map(t => {
       const ruleIdx = compatibleKeys.indexOf(t.camelot_key);