Agent loop state machine refactor, unified LLM interface, and UI improvements

- Rewrite agent loop as Planning→Executing(N)→Completed state machine with
  per-step context isolation to prevent token explosion
- Split tools and prompts by phase (planning vs execution)
- Add advance_step/save_memo tools for step transitions and cross-step memory
- Unify LLM interface: remove duplicate types, single chat_with_tools path
- Add UTF-8 safe truncation (truncate_str) to prevent panics on Chinese text
- Extract CreateForm component, add auto-scroll to execution log
- Add report generation with app access URL, non-blocking title generation
- Add timer system, file serving, app proxy, exec module
- Update Dockerfile with uv, deployment config

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

src/main.rs

@@ -2,13 +2,14 @@ mod api;
 mod agent;
 mod db;
 mod llm;
-mod ssh;
+mod exec;
+mod timer;
 mod ws;
 
 use std::sync::Arc;
 use axum::Router;
 use tower_http::cors::CorsLayer;
-use tower_http::services::ServeDir;
+use tower_http::services::{ServeDir, ServeFile};
 
 pub struct AppState {
     pub db: db::Database,
@@ -19,7 +20,6 @@ pub struct AppState {
 #[derive(Debug, Clone, serde::Deserialize)]
 pub struct Config {
     pub llm: LlmConfig,
-    pub ssh: SshConfig,
     pub server: ServerConfig,
     pub database: DatabaseConfig,
 }
@@ -31,13 +31,6 @@ pub struct LlmConfig {
     pub model: String,
 }
 
-#[derive(Debug, Clone, serde::Deserialize)]
-pub struct SshConfig {
-    pub host: String,
-    pub user: String,
-    pub key_path: String,
-}
-
 #[derive(Debug, Clone, serde::Deserialize)]
 pub struct ServerConfig {
     pub host: String,
@@ -66,9 +59,10 @@ async fn main() -> anyhow::Result<()> {
     let agent_mgr = agent::AgentManager::new(
         database.pool.clone(),
         config.llm.clone(),
-        config.ssh.clone(),
     );
 
+    timer::start_timer_runner(database.pool.clone(), agent_mgr.clone());
+
     let state = Arc::new(AppState {
         db: database,
         config: config.clone(),
@@ -78,7 +72,7 @@ async fn main() -> anyhow::Result<()> {
     let app = Router::new()
         .nest("/api", api::router(state))
         .nest("/ws", ws::router(agent_mgr))
-        .fallback_service(ServeDir::new("web/dist"))
+        .fallback_service(ServeDir::new("web/dist").fallback(ServeFile::new("web/dist/index.html")))
         .layer(CorsLayer::permissive());
 
     let addr = format!("{}:{}", config.server.host, config.server.port);