feat(react): React introspection, Web Vitals, and SPA primitives (#1257)

* feat(react): first-class React introspection, Web Vitals, and nextjs skill

Add React-general and web-universal features as first-class agent-browser verbs
(react tree/inspect/renders/suspense, vitals, pushstate). Genuinely Next.js-specific
workflows (PPR cookie protocol, /_next/mcp bridge, dev-server endpoints) ship as
a new `nextjs` skill that composes the primitives. No new runtime dependencies -
the React DevTools installHook.js is vendored (MIT) and include_str!'d into the
binary.

New commands:
  react tree                  Full React component tree (depth id parent name)
  react inspect <fiberId>     Props, hooks, state, source for one fiber
  react renders start|stop    Fiber profiler with Insts/Mounts/Re-renders/Self/DOM
                              + prev->next change details
  react suspense              Suspense boundaries + classifier (client-hook,
                              request-api, server-fetch, cache, stream, framework)
                              + root-cause grouping + recommendations
  vitals [url]                LCP/CLS/TTFB/FCP/INP + React hydration phases
  pushstate <url>             Generic SPA client-side navigation
  removeinitscript <id>       Remove a script registered via addinitscript

New launch flags:
  --init-script <path>        Register init scripts before first navigation
                              (repeatable; env AGENT_BROWSER_INIT_SCRIPTS)
  --enable <feature>          Built-in init scripts; currently react-devtools
                              (repeatable; env AGENT_BROWSER_ENABLE)

Other primitives:
  network route ... --resource-type <csv>  Filter by CDP resource type
  cookies set --curl <file>                Auto-detects JSON/cURL/Cookie-header

* fixes

* fixes

* fixes

cli/src/native/browser.rs

@@ -1386,6 +1386,18 @@ impl BrowserManager {
             .to_string())
     }
 
+    pub async fn remove_script_to_evaluate(&self, identifier: &str) -> Result<(), String> {
+        let session_id = self.active_session_id()?;
+        self.client
+            .send_command(
+                "Page.removeScriptToEvaluateOnNewDocument",
+                Some(json!({ "identifier": identifier })),
+                Some(session_id),
+            )
+            .await?;
+        Ok(())
+    }
+
     pub async fn tab_switch_by_id(&mut self, tab_id: u32) -> Result<Value, String> {
         let index = self
             .pages