fix(ui): hover-panic on non-ASCII links, paste and clipboard spoofing, image budget, links

- is_web_url sliced the string at byte 7/8, panicking (and killing every
  session) when a remote host printed an OSC 8 or plain link with a
  multi-byte character at that offset and the user hovered it. It now
  compares bytes.
- Paste confirmation also triggers on control characters other than tab
  (readline's C-o runs a line with no newline), and the preview shows
  them escaped.
- Remote clipboard toasts escape control characters and state the line
  count, so 'ls\ncurl … | sh' no longer reads as a harmless 'ls'.
- Inline images: dimensions are read from the header first and anything
  over the 32 Mpx per-terminal budget is refused before decoding.
- Toasts: repeats extend the visible toast and at most 8 are kept, so
  trigger or OSC 52 floods can't stall frames.
- The URL regex is compiled once.
- Enable eframe's 'links' feature: without it every 'open in browser'
  (Cmd/Ctrl+click, GitHub repo links, the update link) was a silent
  no-op. Adds webbrowser 1.2.4 to the lockfile.

rust/Cargo.lock

@@ -1800,6 +1800,7 @@ dependencies = [
  "serde",
  "smithay-clipboard",
  "web-time",
+ "webbrowser",
  "winit",
 ]
 
@@ -7074,6 +7075,22 @@ dependencies = [
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "webbrowser"
+version = "1.2.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "62c35be770821a214dbc362fc26908c853e776c0004294d0b10b8a6bad582f94"
+dependencies = [
+ "jni 0.22.4",
+ "log",
+ "ndk-context",
+ "objc2 0.6.5",
+ "objc2-app-kit 0.3.2",
+ "objc2-foundation 0.3.2",
+ "url",
+ "web-sys",
+]
+
 [[package]]
 name = "webpki-roots"
 version = "1.0.9"