Drop cookie import; click-through notifications; per-app zoom

The cookie import is gone. It worked mechanically - 43 cookies decrypted
from Arc and verifiably visible to the page - but Google, Microsoft and
Odoo all refused the imported sessions, because each binds a session to
the browser that created it. Signing in once inside the app is simpler
and actually works, so the whole path is deleted rather than kept as a
feature that mostly fails. That takes rusqlite, aes, cbc, pbkdf2, hmac,
sha1 and sha2 out of the build with it.

Notifications are now raised through mac-notification-sys rather than
Tauri's notification plugin, because the plugin cannot report that one
was clicked. A click switches to the app that raised it and then runs
the page's own click handler - the only thing that knows which message
the notification was about.

Zoom is per app, on a fixed ladder so Cmd+0 returns to exactly 100%.
The shortcuts are menu-bar accelerators rather than a key listener,
since the keystroke has to work while a remote page has focus.

The hidden-element count is off the nav rows.

src-tauri/Cargo.toml

@@ -23,16 +23,9 @@ tokio = { version = "1", features = ["time"] }
 url = "2"
 uuid = { version = "1", features = ["v4"] }
 
-# Browser cookie import.
-rusqlite = { version = "0.40.2", features = ["bundled"] }
-aes = "0.8"
-cbc = { version = "0.1", features = ["alloc"] }
-pbkdf2 = { version = "0.12", default-features = false, features = ["hmac"] }
-hmac = "0.12"
-sha1 = "0.10"
-sha2 = "0.10"
-
 [target.'cfg(target_os = "macos")'.dependencies]
 objc2 = "0.6"
-objc2-foundation = { version = "0.3", features = ["NSHTTPCookie", "NSString", "NSDictionary", "NSArray", "NSDate", "NSValue", "NSURL"] }
-objc2-web-kit = { version = "0.3.2", features = ["WKWebView", "WKWebViewConfiguration", "WKPreferences", "WKWebsiteDataStore", "WKHTTPCookieStore"] }
+objc2-web-kit = { version = "0.3.2", features = ["WKWebView", "WKWebViewConfiguration", "WKPreferences"] }
+# Notifications are raised here rather than through the plugin, which offers no
+# way to learn that one was clicked.
+mac-notification-sys = "0.6"