Bulk tagging + channel-name search

Bulk tagging
- Desktop bulk-mode toolbar grows three new buttons next to ✓ Watched
  and ○ Unwatched: ★ Favourite, 🔖 Bookmark, ⏳ Waiting. Each applies
  the corresponding flag to every video in the current bulk selection.
- New `App::bulk_set_flag` mirrors the existing `bulk_mark_watched`:
  iterates selection, persists each flag via `Database::set_video_flag`,
  mirrors into the in-memory `flags` bundle, busts the cards-cache so
  the smart-folder counts refresh on the next render.
- Web bulk-actions row gets the same three buttons. New `bulkFlag(flag)`
  fires the POSTs in parallel via Promise.all and reloads the library
  once they complete.
- Tagging in bulk only ever sets a flag — no toggle. Removing flags in
  bulk is rarely what users want; the per-card buttons handle un-flag.

Channel-name search
- Both UIs already filter by video title + id; extend to match the
  channel name too. Searching "Linus" now surfaces every video from a
  channel called "Linus Tech Tips" without typing the title.
- Description matching deliberately skipped — would require reading the
  .description sidecar per-video per-keystroke. Mentioned in the code
  comment as a future "load descriptions into the search index on
  rescan" pass if real users want it.
- New JS helper `matchesSearch(v, chName, q)` centralises the four
  call sites in `currentVideos()` (continue / recent / smart-folder /
  default).

55 unit tests pass.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/app.rs

@@ -451,9 +451,14 @@ impl App {
         let mut cards = Vec::new();
 
         let add_video = |cards: &mut Vec<Card>, ch_name: &str, v: &library::Video| {
+            // Search matches title / id / channel name. Description matching
+            // would require reading the .description sidecar per-video on every
+            // keystroke — punted to a future "load descriptions into the
+            // search index on rescan" pass if users ask for it.
             if !query.is_empty()
                 && !v.title.to_lowercase().contains(&query)
                 && !v.id.to_lowercase().contains(&query)
+                && !ch_name.to_lowercase().contains(&query)
             {
                 return;
             }
@@ -762,6 +767,32 @@ impl App {
         );
     }
 
+    /// Bulk-apply a single per-video flag (`"bookmark"` / `"favourite"` /
+    /// `"waiting"` / `"archive"`) across the current selection. Same shape
+    /// as [`bulk_mark_watched`], extended for the smart-folder flag set.
+    fn bulk_set_flag(&mut self, flag: &'static str, value: bool) {
+        let ids: Vec<String> = self.bulk_selected.iter().cloned().collect();
+        let count = ids.len();
+        for id in &ids {
+            if self.db.set_video_flag(id, flag, value).is_err() { continue; }
+            let set = match flag {
+                "bookmark" => &mut self.flags.bookmark,
+                "favourite" => &mut self.flags.favourite,
+                "waiting" => &mut self.flags.waiting,
+                "archive" => &mut self.flags.archive,
+                _ => return,
+            };
+            if value { set.insert(id.clone()); } else { set.remove(id); }
+        }
+        self.bulk_selected.clear();
+        self.cards_cache_key = None;
+        self.status = format!(
+            "{count} {} {}{flag}",
+            if count == 1 { "video" } else { "videos" },
+            if value { "→ " } else { "un" },
+        );
+    }
+
     fn run_scheduled_check(&mut self) {
         // Snapshot each channel's URL + options first so we don't hold an
         // immutable borrow of `self.library` while calling
@@ -2623,14 +2654,26 @@ impl App {
                 ui.separator();
                 let n = self.bulk_selected.len();
                 ui.label(format!("{n} selected"));
-                if ui.button("✓ Mark watched").clicked() {
+                if ui.button("✓ Watched").clicked() {
                     self.bulk_mark_watched(true);
                     self.bulk_mode = false;
                 }
-                if ui.button("○ Mark unwatched").clicked() {
+                if ui.button("○ Unwatched").clicked() {
                     self.bulk_mark_watched(false);
                     self.bulk_mode = false;
                 }
+                if ui.button("★ Favourite").on_hover_text("Mark every selected video as favourite").clicked() {
+                    self.bulk_set_flag("favourite", true);
+                    self.bulk_mode = false;
+                }
+                if ui.button("🔖 Bookmark").on_hover_text("Mark every selected video as bookmarked").clicked() {
+                    self.bulk_set_flag("bookmark", true);
+                    self.bulk_mode = false;
+                }
+                if ui.button("⏳ Waiting").on_hover_text("Add every selected video to the waiting list").clicked() {
+                    self.bulk_set_flag("waiting", true);
+                    self.bulk_mode = false;
+                }
             }
 
             ui.with_layout(egui::Layout::right_to_left(egui::Align::Center), |ui| {