Multi-select, paste-to-app, resizable window, polished UI

- Max history default increased to 10K, options: 1K/5K/10K/50K
- Tray icon uses with_id to prevent duplicates on hot-reload
- Selecting an entry now pastes directly into the previous app
  via osascript Cmd+V simulation after hiding the window
- Multi-select: Ctrl+Click toggles, Shift+Arrow extends range,
  Cmd+A selects all, Enter pastes all selected
- Window is resizable, size persists in SQLite across opens
- Window position setting: cursor, center, or any screen corner
- UI cleanup: tighter spacing, cleaner dividers, compact search,
  type badges (TXT/IMG/FILE), PIN label, tabular timestamps
- Context menu shows multi-item labels ("Paste 3 items")
- All tests updated and passing (27 Rust + 33 TypeScript)

Co-authored-by: Cursor <cursoragent@cursor.com>

src-tauri/Cargo.lock

@@ -1961,6 +1961,7 @@ dependencies = [
  "tauri-plugin-autostart",
  "tauri-plugin-clipboard-manager",
  "tauri-plugin-global-shortcut",
+ "tokio",
 ]
 
 [[package]]
@@ -3728,9 +3729,21 @@ dependencies = [
  "mio",
  "pin-project-lite",
  "socket2",
+ "tokio-macros",
  "windows-sys 0.61.2",
 ]
 
+[[package]]
+name = "tokio-macros"
+version = "2.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "385a6cb71ab9ab790c5fe8d67f1645e6c450a7ce006a33de03daa956cf70a496"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.117",
+]
+
 [[package]]
 name = "tokio-util"
 version = "0.7.18"