fix: login/signup flow working with session-based auth

- Fixed hashPasswordIO to use real PBKDF2 hashing from Sis.Auth
- Added seed route (rseed) for demo data initialization
- Replaced redirect() in update functions with success views
  (redirect uses throwError_ which broke with effectful 2.4)
- Added loginSuccessView and signupSuccessView with dashboard links
- Patched Hyperbole Socket.hs to parse WebSocket form body into Form params
- Patched Hyperbole Wai.hs to include TargetViewId in response metadata
- Fixed View/Page type mismatches (hyper wrapper vs plain view)
- Removed dead pure after redirect calls
- Verified: login submits, session set, success view rendered

package.json

@@ -0,0 +1,5 @@
+{
+  "dependencies": {
+    "playwright": "^1.61.1"
+  }
+}