docs: Remove incorrect state wrapper in session post payload

docs/deploy/cloud-run.md

@@ -446,7 +446,7 @@ Once your agent is deployed to Cloud Run, you can interact with it via the deplo
     curl -X POST -H "Authorization: Bearer $TOKEN" \
         $APP_URL/apps/capital_agent/users/user_123/sessions/session_abc \
         -H "Content-Type: application/json" \
-        -d '{"state": {"preferred_language": "English", "visit_count": 5}}'
+        -d '{"preferred_language": "English", "visit_count": 5}'
     ```
 
     #### Run the Agent

docs/deploy/gke.md

@@ -523,7 +523,7 @@ Once your agent is deployed to GKE, you can interact with it via the deployed UI
     curl -X POST \
         $APP_URL/apps/capital_agent/users/user_123/sessions/session_abc \
         -H "Content-Type: application/json" \
-        -d '{"state": {"preferred_language": "English", "visit_count": 5}}'
+        -d '{"preferred_language": "English", "visit_count": 5}'
     ```
 
     #### Run the Agent

docs/get-started/testing.md

@@ -98,7 +98,7 @@ a new session with the agent using:
 ```shell
 curl -X POST http://localhost:8000/apps/my_sample_agent/users/u_123/sessions/s_123 \
   -H "Content-Type: application/json" \
-  -d '{"state": {"key1": "value1", "key2": 42}}'
+  -d '{"key1": "value1", "key2": 42}'
 ```
 
 Let's break down what's happening:
@@ -109,7 +109,7 @@ Let's break down what's happening:
   can replace `my_sample_agent` with the name of your agent folder. You can
   replace `u_123` with a specific user ID, and `s_123` with a specific session
   ID.
-* `{"state": {"key1": "value1", "key2": 42}}`: This is optional. You can use
+* `{"key1": "value1", "key2": 42}`: This is optional. You can use
   this to customize the agent's pre-existing state (dict) when creating the
   session.
 
@@ -321,18 +321,16 @@ Creates a new session or updates an existing one. If a session with the given ID
 **Request Body**
 ```json
 {
-  "state": {
-    "key1": "value1",
-    "key2": 42
-  }
+  "key1": "value1",
+  "key2": 42
 }
 ```
 
 **Example Request**
 ```shell
 curl -X POST http://localhost:8000/apps/my_sample_agent/users/u_123/sessions/s_abc \
   -H "Content-Type: application/json" \
-  -d '{"state": {"visit_count": 5}}'
+  -d '{"visit_count": 5}'
 ```
 
 **Example Response**