feat: align browser callback runtime and export flows

Consolidate the browser task runtime around the callback path, add safer artifact opening for Zhihu exports, and cover the new service/browser flows with focused tests and supporting docs.

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

src/agent/mod.rs

@@ -1,45 +1,16 @@
-pub mod planner;
-pub mod runtime;
 pub mod task_runner;
 
 use std::sync::Arc;
 
 use crate::browser::ws_backend::WsBrowserBackend;
 use crate::browser::{BrowserBackend, PipeBrowserBackend};
-use crate::pipe::{AgentMessage, BrowserMessage, BrowserPipeTool, PipeError, Transport};
+use crate::pipe::{BrowserMessage, BrowserPipeTool, PipeError, Transport};
 
 pub use task_runner::{
     run_submit_task, run_submit_task_with_browser_backend, AgentEventSink, AgentRuntimeContext,
     SubmitTaskRequest,
 };
 
-fn execute_plan<T: Transport>(
-    transport: &T,
-    browser_tool: &BrowserPipeTool<T>,
-    plan: &planner::TaskPlan,
-) -> Result<String, PipeError> {
-    for step in &plan.steps {
-        transport.send(&AgentMessage::LogEntry {
-            level: "info".to_string(),
-            message: step.log_message.clone(),
-        })?;
-
-        let result = browser_tool.invoke(
-            step.action.clone(),
-            step.params.clone(),
-            &step.expected_domain,
-        )?;
-        if !result.success {
-            return Err(PipeError::Protocol(format!(
-                "browser action failed: {}",
-                result.data
-            )));
-        }
-    }
-
-    Ok(plan.summary.clone())
-}
-
 fn normalize_optional_submit_field(value: String) -> Option<String> {
     let trimmed = value.trim();
     (!trimmed.is_empty()).then(|| trimmed.to_string())
@@ -82,21 +53,11 @@ fn configured_browser_ws_url(context: &AgentRuntimeContext) -> Option<String> {
 }
 
 fn send_status_changed<T: Transport>(transport: &T, state: &str) -> Result<(), PipeError> {
-    transport.send(&AgentMessage::StatusChanged {
+    transport.send(&crate::pipe::AgentMessage::StatusChanged {
         state: state.to_string(),
     })
 }
 
-pub fn execute_task<T: Transport>(
-    transport: &T,
-    browser_tool: &BrowserPipeTool<T>,
-    instruction: &str,
-) -> Result<String, PipeError> {
-    let plan = planner::plan_instruction(instruction)
-        .map_err(|err| PipeError::Protocol(err.to_string()))?;
-    execute_plan(transport, browser_tool, &plan)
-}
-
 pub fn handle_browser_message<T: Transport + 'static>(
     transport: &T,
     browser_tool: &BrowserPipeTool<T>,
@@ -151,6 +112,8 @@ pub fn handle_browser_message_with_context<T: Transport + 'static>(
 #[cfg(test)]
 mod tests {
     use super::normalize_optional_submit_field;
+    use std::fs;
+    use std::path::PathBuf;
 
     #[test]
     fn normalize_optional_submit_field_trims_and_drops_blank_values() {
@@ -160,4 +123,21 @@ mod tests {
             Some("https://example.com/page".to_string())
         );
     }
+
+    #[test]
+    fn agent_module_cleanup_removes_legacy_runtime_and_planner_sources() {
+        let manifest_dir = PathBuf::from(env!("CARGO_MANIFEST_DIR"));
+        let agent_module = fs::read_to_string(manifest_dir.join("src/agent/mod.rs")).unwrap();
+        let top_lines = agent_module
+            .lines()
+            .take(10)
+            .map(str::trim)
+            .collect::<Vec<_>>();
+
+        assert!(!manifest_dir.join("src/agent/runtime.rs").exists());
+        assert!(!manifest_dir.join("src/agent/planner.rs").exists());
+        assert!(!top_lines.iter().any(|line| *line == "pub mod runtime;"));
+        assert!(!top_lines.iter().any(|line| *line == "pub mod planner;"));
+        assert!(top_lines.iter().any(|line| *line == "pub mod task_runner;"));
+    }
 }