Browser pairing, notifications, element hiding; drop the top bar

Pairing decrypts a Chromium browser's cookie store (PBKDF2-HMAC-SHA1
against its Keychain key, then AES-128-CBC) and injects the result into
WKHTTPCookieStore. Only the configured apps' hosts and their sign-in
hosts survive the filter. Browsers are offered most-recently-used first,
since the first entry becomes the default and someone with four
Chromium browsers installed wants the one they actually browse in.

WKWebView defines window.Notification but it does nothing: constructing
one throws no error and shows no banner, so a page believes it notified
you. Measured on the machine as `api=function shim=no` before the shim
was made unconditional; `from page: Odoo - Test notification -> raised`
after.

Anything on a page can be right-clicked away. The rule is re-asserted on
every navigation, because the injected script only carries a snapshot
from when the view was built and a selector added since would otherwise
come back on reload.

The top bar is gone. Navigation lives beside the cog, the nav carries
the traffic lights, and two-finger swipe goes back and forward.

The seed is now the real app list, scoped to exact hosts so a Drive link
inside Gmail switches rather than being swallowed.

src-tauri/Cargo.toml

@@ -16,8 +16,23 @@ tauri-build = { version = "2", features = [] }
 # Pinned: multi-webview lives behind `unstable`, whose API can move between minors.
 tauri = { version = "=2.11.5", features = ["unstable"] }
 tauri-plugin-opener = "2"
+tauri-plugin-notification = "2"
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
 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"] }