fix: plugin event shape mismatches, nav highlight bug, and README update

- Fix session.created/deleted reading props.info.id instead of props.id
- Fix session.diff reading FileDiff[] array instead of string
- Fix file.edited reading props.file instead of props.filePath
- Add auto-session creation fallback from tool/chat hooks
- Add flushSession() for intermediate trace sends on session.idle
- Fix dashboard nav: /dashboard exact match prevents false active state
- Update README with TypeScript SDK and OpenCode plugin sections

apps/web/src/app/dashboard/layout.tsx

@@ -51,7 +51,11 @@ function Sidebar({ onNavigate }: { onNavigate?: () => void }) {
       <nav className="flex-1 p-4 space-y-1">
         {navItems.map((item) => {
           const Icon = item.icon;
-          const isActive = pathname === item.href || pathname.startsWith(`${item.href}/`);
+          const isActive =
+            item.href === "/dashboard"
+              ? pathname === "/dashboard"
+              : pathname === item.href ||
+                pathname.startsWith(`${item.href}/`);
 
           return (
             <Link