fix(deps): resolve 15 Dependabot security vulnerabilities

- undici: updated to fix WebSocket memory exhaustion, CRLF injection,
  HTTP smuggling, and 64-bit length overflow (10 alerts)
- devalue: updated to fix prototype pollution in parse/unflatten (2 alerts)
- serialize-javascript: override to >=7.0.3 fixes RCE via RegExp.flags (1 alert)
- glib 0.18.5: unsound Iterator impls — upstream tauri dependency,
  cannot update without tauri releasing gtk-rs 0.22 support (1 alert, low risk)

Resolves all npm vulnerabilities (0 remaining). 1 Rust advisory remains
(glib, pinned by tauri gtk-rs dependency chain).

package.json

@@ -34,6 +34,9 @@
     "vite": "^7.3.1",
     "vitest": "^4.0.18"
   },
+  "overrides": {
+    "serialize-javascript": ">=7.0.3"
+  },
   "dependencies": {
     "@anthropic-ai/claude-agent-sdk": "^0.2.70",
     "@codemirror/lang-cpp": "^6.0.3",