feat: add websocket browser service runtime

Wire the service/browser runtime onto the websocket-driven execution path and add the new browser/service modules needed for the submit flow and runtime integration.

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

src/browser/bridge_contract.rs

@@ -0,0 +1,63 @@
+use serde::{Deserialize, Serialize};
+use serde_json::Value;
+
+use crate::pipe::Timing;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum BridgeLifecycleCall {
+    Connect,
+    Start,
+    Stop,
+    SubmitTask,
+}
+
+impl BridgeLifecycleCall {
+    pub fn bridge_name(self) -> &'static str {
+        match self {
+            Self::Connect => "sgclawConnect",
+            Self::Start => "sgclawStart",
+            Self::Stop => "sgclawStop",
+            Self::SubmitTask => "sgclawSubmitTask",
+        }
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct BridgeBrowserActionRequest {
+    pub action: String,
+    pub params: Value,
+    pub expected_domain: String,
+}
+
+impl BridgeBrowserActionRequest {
+    pub fn new(
+        action: impl Into<String>,
+        params: Value,
+        expected_domain: impl Into<String>,
+    ) -> Self {
+        Self {
+            action: action.into(),
+            params,
+            expected_domain: expected_domain.into(),
+        }
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub enum BridgeBrowserActionReply {
+    Success(BridgeBrowserActionSuccess),
+    Error(BridgeBrowserActionError),
+}
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct BridgeBrowserActionSuccess {
+    pub data: Value,
+    pub aom_snapshot: Vec<Value>,
+    pub timing: Timing,
+}
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct BridgeBrowserActionError {
+    pub message: String,
+    pub details: Value,
+}