fix: smart playlist UX polish — layout, defaults, free-form input, case-insensitive matching

Details view:
- Skip evaluation on new playlists (was returning all 25k tracks)
- Go straight to editor on auto-edit instead of awaiting loadTracks

Editor:
- Default sort to Random instead of None, remove None option
- Hide sort direction button when sort is Random
- Fixed-width field (160px) and operator (140px) columns, value fills remaining space
- Preview fills remaining vertical space (flex layout) instead of fixed 200px max-height
- Preview scrolls independently while rules/options stay pinned

Combobox:
- Accept free-form text on blur and Enter — no longer requires selection from dropdown
- Enables typing values like 'indie' that may not be exact DB entries

Backend:
- Case-insensitive text matching: COLLATE NOCASE on is/is_not/is_any_of operators
- Applies to both regular fields and genre subqueries
- LIKE operators were already case-insensitive (SQLite default)

frontend/src/components/smart-playlist-details/smart-playlist-details.ts

@@ -261,8 +261,11 @@ export class SmartPlaylistDetails extends LitElement {
 
         .editor-container {
             flex: 1;
-            overflow: auto;
+            overflow: hidden;
             padding: 0 20px 20px;
+            display: flex;
+            flex-direction: column;
+            min-height: 0;
         }
     `];
 
@@ -270,13 +273,17 @@ export class SmartPlaylistDetails extends LitElement {
     // Lifecycle
     // =================================================================
 
-    override async connectedCallback() {
+    override connectedCallback() {
         super.connectedCallback();
-        await this.loadTracks();
 
         if (this.autoEdit) {
+            // Skip evaluation for new playlists — go straight to editor.
             this.autoEdit = false;
+            this.loading = false;
+            this.tracks = [];
             this.handleEditRules();
+        } else {
+            void this.loadTracks();
         }
 
         this.playlistDeletedCleanup = EventsOn(