Expose managed application network requirements (#42417)

## What changed

- Add `application.network` managed requirements with exact-domain allow/deny
  rules, default-enabled behavior, domain normalization, and normal managed TOML
  precedence.
- Return the policy separately from agent network requirements through the
  experimental `configRequirements/read` API. The endpoint reports the policy
  but does not enforce it.
- Export the new protocol types and schemas, and document the TOML format.

## Testing

- Cover parsing, validation, normalization, layered precedence, and cloud
  requirement composition.
- Verify app-server responses, defaults, separation from agent policy, and
  rejection of invalid domains.

GitOrigin-RevId: 563eeed296d9748430b819797204a44a8db92f3b

codex-rs/app-server-protocol/schema/json/v2/ConfigRequirementsReadResponse.json

@@ -8,6 +8,40 @@
       ],
       "type": "string"
     },
+    "ApplicationNetworkRequirements": {
+      "properties": {
+        "domains": {
+          "additionalProperties": {
+            "$ref": "#/definitions/NetworkDomainPermission"
+          },
+          "type": "object"
+        },
+        "enabled": {
+          "description": "When enabled, only explicitly allowed exact domains may be contacted.",
+          "type": "boolean"
+        }
+      },
+      "required": [
+        "domains",
+        "enabled"
+      ],
+      "type": "object"
+    },
+    "ApplicationRequirements": {
+      "properties": {
+        "network": {
+          "anyOf": [
+            {
+              "$ref": "#/definitions/ApplicationNetworkRequirements"
+            },
+            {
+              "type": "null"
+            }
+          ]
+        }
+      },
+      "type": "object"
+    },
     "ApprovalsReviewer": {
       "description": "Configures who approval requests are routed to for review. Examples include sandbox escapes, blocked network access, MCP approval prompts, and ARC escalations. Defaults to `user`. `auto_review` uses a carefully prompted subagent to gather relevant context and apply a risk-based decision framework before approving or denying the request. The legacy value `guardian_subagent` is accepted for compatibility.",
       "enum": [