fix(e2e): fix workflowui playwright test URLs and login style

auth.json:
- Change absolute URLs (/login, /register) to relative (login, register)
  so Playwright resolves them against baseURL /workflowui/ correctly
- Add switch-to-material click before auth-layout assertions, since
  login page defaults to Salesforce style

templates.json:
- Change absolute URLs (/templates, /templates/1) to relative
- Add waitForLoadState before category filter click

Root cause: basePath='/workflowui' + absolute URL '/login' resolves
to http://localhost:3000/login (404), not /workflowui/login

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontends/workflowui/playwright/auth.json

@@ -9,12 +9,17 @@
       "steps": [
         {
           "action": "navigate",
-          "url": "/login"
+          "url": "login"
         },
         {
           "action": "waitForLoadState",
           "state": "networkidle"
         },
+        {
+          "description": "Switch to Material Design style",
+          "action": "click",
+          "testId": "switch-to-material"
+        },
         {
           "description": "Verify auth layout visible",
           "action": "expect",
@@ -55,7 +60,7 @@
       "steps": [
         {
           "action": "navigate",
-          "url": "/register"
+          "url": "register"
         },
         {
           "action": "waitForLoadState",
@@ -99,7 +104,16 @@
       "steps": [
         {
           "action": "navigate",
-          "url": "/login"
+          "url": "login"
+        },
+        {
+          "action": "waitForLoadState",
+          "state": "networkidle"
+        },
+        {
+          "description": "Switch to Material Design style",
+          "action": "click",
+          "testId": "switch-to-material"
         },
         {
           "action": "fill",
@@ -127,7 +141,7 @@
       "steps": [
         {
           "action": "navigate",
-          "url": "/register"
+          "url": "register"
         },
         {
           "action": "waitForLoadState",
@@ -158,7 +172,7 @@
       "steps": [
         {
           "action": "navigate",
-          "url": "/nonexistent-page-12345"
+          "url": "nonexistent-page-12345"
         },
         {
           "action": "waitForLoadState",
@@ -205,7 +219,7 @@
       "steps": [
         {
           "action": "navigate",
-          "url": "/"
+          "url": ""
         },
         {
           "action": "waitForLoadState",

frontends/workflowui/playwright/templates.json

@@ -10,7 +10,7 @@
       "steps": [
         {
           "action": "navigate",
-          "url": "/templates"
+          "url": "templates"
         },
         {
           "action": "waitForLoadState",
@@ -48,7 +48,11 @@
       "steps": [
         {
           "action": "navigate",
-          "url": "/templates"
+          "url": "templates"
+        },
+        {
+          "action": "waitForLoadState",
+          "state": "networkidle"
         },
         {
           "action": "click",
@@ -74,7 +78,11 @@
       "steps": [
         {
           "action": "navigate",
-          "url": "/templates"
+          "url": "templates"
+        },
+        {
+          "action": "waitForLoadState",
+          "state": "networkidle"
         },
         {
           "action": "click",
@@ -112,7 +120,11 @@
       "steps": [
         {
           "action": "navigate",
-          "url": "/templates"
+          "url": "templates"
+        },
+        {
+          "action": "waitForLoadState",
+          "state": "networkidle"
         },
         {
           "action": "click",
@@ -146,7 +158,11 @@
       "steps": [
         {
           "action": "navigate",
-          "url": "/templates/1"
+          "url": "templates/1"
+        },
+        {
+          "action": "waitForLoadState",
+          "state": "networkidle"
         },
         {
           "action": "click",