diff --git a/AGENTS.md b/AGENTS.md
index f19d4a4..70d4d02 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -96,12 +96,14 @@ let b = self.buf.pop_front();
 
 | crate | 推荐 tokio features |
 |---|---|
-| `focus-core` | `rt`, `sync`, `macros` |
-| `focus-transport` | `rt`, `net`, `io-util`, `sync` |
-| `focus-providers` | `rt`, `sync`, `macros` |
+| `focus-core` | （无 tokio —— 核心层为纯同步逻辑） |
+| `focus-transport` | `net`, `io-util`, `time`（TCP/TLS、超时） |
+| `focus-providers` | `rt`, `time`（后台 current-thread 运行时） |
 | `focus-tools` | （无 tokio —— 工具为同步 `std` I/O） |
 | `focus-harness` | （无 tokio —— 会话/压缩为纯逻辑 + 同步 `std` I/O） |
 
+> workspace 级 `tokio` 声明不带 features；由各成员按上表自行声明。
+
 ### 2.3 Rust 版本
 
 - 使用**最新 stable** Rust。
@@ -189,8 +191,9 @@ focus-tui        ←  focus-core, focus-providers, focus-tools, focus-harness, f
   （`~/.focus/config.json`，TUI 内 `/config` 编辑；provider 构造时传入）、动态系统
   提示注入（方案 E 的 Usage/上下文占用）、自动上下文压缩的执行（harness 产出方案 →
   调 provider 摘要 → `Agent::replace_messages` 写回）、会话持久化（`~/.focus/sessions/`）。
-- **交互**：多行输入、流式显示、Esc 中止、折叠的思考/工具块（显示耗时与内容摘要，
-  点击或 Tab 展开）、命令（`/new` `/sessions` `/config` `/compact`）。
+- **交互**：多行输入、Markdown 渲染、流式显示、Esc 中止、折叠的思考/工具块
+  （显示耗时与内容摘要，点击或 Tab 两级展开——先预览后全量）、工具请求与结果合并
+  为一块、命令（`/new` `/sessions` `/config` `/compact`）。
 - **禁止**：把业务逻辑放这里。这里只做**组装与呈现**。
 
 ## 4. 代码规范
diff --git a/Cargo.lock b/Cargo.lock
index 386b4db..5c113a6 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -429,7 +429,6 @@ name = "focus-core"
 version = "0.1.0"
 dependencies = [
  "focus-json",
- "tokio",
 ]
 
 [[package]]
@@ -1702,23 +1701,10 @@ dependencies = [
  "libc",
  "mio",
  "pin-project-lite",
- "signal-hook-registry",
  "socket2",
- "tokio-macros",
  "windows-sys 0.61.2",
 ]
 
-[[package]]
-name = "tokio-macros"
-version = "2.7.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "385a6cb71ab9ab790c5fe8d67f1645e6c450a7ce006a33de03daa956cf70a496"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn 2.0.119",
-]
-
 [[package]]
 name = "tokio-rustls"
 version = "0.26.4"
diff --git a/Cargo.toml b/Cargo.toml
index 908cb34..b5f2e20 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -26,7 +26,9 @@ license = "MIT"
 
 [workspace.dependencies]
 # --- allowed runtime dependencies (see AGENTS.md §2.1) ---------------------
-tokio = { version = "1", features = ["rt", "sync", "macros", "net", "io-util", "fs", "process", "rt-multi-thread", "signal", "time"] }
+# tokio features 由各成员 crate 按需声明（见 AGENTS.md §2.2）。
+# Each member declares the tokio features it actually needs (see AGENTS.md §2.2).
+tokio = { version = "1" }
 rustls = { version = "0.23", default-features = false, features = ["ring", "std"] }
 tokio-rustls = { version = "0.26", default-features = false, features = ["ring", "logging", "tls12"] }
 rustls-native-certs = "0.7"
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..87aaa5a
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 focus contributors
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/README.md b/README.md
index d81c231..d8574f3 100644
--- a/README.md
+++ b/README.md
@@ -62,7 +62,7 @@ focus-tui         ←  focus-core, focus-providers, focus-tools, focus-harness,
 # 构建整个 workspace
 cargo build --workspace
 
-# 运行全部测试（177 个用例，全绿）
+# 运行全部测试（181 个用例，全绿）
 cargo test --workspace
 
 # 代码质量检查
@@ -116,6 +116,14 @@ cargo run -p focus-tui
 | 配置 | `<data>/config.json` |
 | 会话 | `<data>/sessions/<session-id>.jsonl`（JSONL 追加写，树结构） |
 
+### 环境变量
+
+| 变量 | 说明 |
+|---|---|
+| `FOCUS_DATA_DIR` | 覆盖数据根目录（默认 `~/.focus`） |
+| `FOCUS_SHELL` | 覆盖 `shell` 工具使用的 shell 程序（Windows 默认 PowerShell、可回退 cmd；Linux 默认 bash） |
+| `FOCUS_DEBUG_FILE` | 设置后，providers 把每个原始网络 chunk 追加到该文件（排查协议不兼容，如推理字段名差异） |
+
 ## ⌨️ TUI 使用
 
 ### 命令
@@ -137,7 +145,8 @@ cargo run -p focus-tui
 | `Esc` | 运行中中止任务；空闲时退出 |
 | `Ctrl+C` | 退出 |
 | `Ctrl+D` | 继续（追问一轮） |
-| `Tab` | 展开 / 折叠最近的思考或工具块 |
+| `Tab` | 展开 / 折叠最近的思考或工具块（两级：先预览，再全量） |
+| 鼠标滚轮 | 逐行滚动（Linux / Windows 均支持；上滚暂停自动跟随） |
 | `Ctrl+U` / `PageUp` / `PageDown` | 滚动消息区（输入为空时 `↑` `↓` 也可滚动） |
 
 ## 🧪 测试
@@ -145,7 +154,7 @@ cargo run -p focus-tui
 - 所有测试位于各 crate 的 `crates/<name>/tests/`，禁止在 `src/` 内联测试
 - 核心层（`focus-core`）测试**零网络依赖**，用 mock provider 驱动
 - provider 测试用**录制 / 回放**的 mock transport，不打真实 API（真实 API 测试用 `#[ignore]` 标记）
-- 当前共 **177 个测试用例**，`cargo test --workspace` 全绿
+- 当前共 **181 个测试用例**，`cargo test --workspace` 全绿
 
 ## 📚 文档
 
diff --git a/crates/focus-core/Cargo.toml b/crates/focus-core/Cargo.toml
index d64bb3d..a7b2ddf 100644
--- a/crates/focus-core/Cargo.toml
+++ b/crates/focus-core/Cargo.toml
@@ -7,5 +7,6 @@ license.workspace = true
 description = "Core agent layer: domain types, agent loop, tool and provider traits"
 
 [dependencies]
+# 核心层是纯同步逻辑（同步拉取式流模型），不依赖任何运行时。
+# The core layer is purely synchronous (pull-based streaming); no runtime.
 focus-json.workspace = true
-tokio = { workspace = true, features = ["rt", "sync", "macros"] }
diff --git a/crates/focus-core/src/agent.rs b/crates/focus-core/src/agent.rs
index 95d47e7..d9c3c11 100644
--- a/crates/focus-core/src/agent.rs
+++ b/crates/focus-core/src/agent.rs
@@ -434,10 +434,6 @@ impl std::fmt::Debug for Agent {
     }
 }
 
-/// 一次运行返回的句柄（目前仅作信息用途）。
-/// A handle returned from a run (currently just informational).
-pub struct AgentHandle;
-
 /// 一批已执行工具调用的结果。
 /// The results of one executed batch of tool calls.
 struct ExecutedBatch {
diff --git a/crates/focus-core/src/lib.rs b/crates/focus-core/src/lib.rs
index 59912c2..2f18578 100644
--- a/crates/focus-core/src/lib.rs
+++ b/crates/focus-core/src/lib.rs
@@ -33,7 +33,7 @@ pub mod provider;
 /// The `Tool` trait, effects bitflag, and tool registry.
 pub mod tool;
 
-pub use agent::{Agent, AgentConfig, AgentHandle};
+pub use agent::{Agent, AgentConfig};
 pub use error::{CoreError, CoreResult};
 pub use event::{AgentEvent, EventSink};
 pub use model::*;
diff --git a/crates/focus-providers/Cargo.toml b/crates/focus-providers/Cargo.toml
index 45fd6e6..26c5709 100644
--- a/crates/focus-providers/Cargo.toml
+++ b/crates/focus-providers/Cargo.toml
@@ -10,7 +10,7 @@ description = "LLM provider implementations (Anthropic, OpenAI) for the focus ag
 focus-core.workspace = true
 focus-transport.workspace = true
 focus-json.workspace = true
-tokio = { workspace = true, features = ["rt", "sync", "macros"] }
+tokio = { workspace = true, features = ["rt", "time"] }
 
 [dev-dependencies]
 focus-harness.workspace = true
diff --git a/crates/focus-providers/tests/compaction_integration.rs b/crates/focus-providers/tests/compaction_integration.rs
index 5922461..6394efb 100644
--- a/crates/focus-providers/tests/compaction_integration.rs
+++ b/crates/focus-providers/tests/compaction_integration.rs
@@ -165,10 +165,9 @@ fn full_conversation_compaction_and_continue() {
     // Re-inject a provider (the mock is single-use).
     let provider =
         AnthropicProvider::with_transport(ProviderConfig::new("sk-test"), Arc::new(mock3));
-    agent.replace_messages(agent.messages().to_vec());
-    // 通过内部字段替换 provider：直接重建 agent 以保留消息。
-    // Rebuild the agent keeping the transcript, since the provider is not
-    // swappable on an existing agent.
+    // provider 不可在既有 agent 上替换，重建 agent 并保留 transcript。
+    // The provider is not swappable on an existing agent; rebuild it keeping
+    // the transcript.
     let mut agent2 = Agent::new(
         AgentConfig {
             model: "claude-sonnet-4".into(),
diff --git a/crates/focus-transport/Cargo.toml b/crates/focus-transport/Cargo.toml
index 0be145a..2a07cfc 100644
--- a/crates/focus-transport/Cargo.toml
+++ b/crates/focus-transport/Cargo.toml
@@ -8,7 +8,7 @@ description = "Transport layer: HTTPS client (tokio + rustls), HTTP/1.1, SSE par
 
 [dependencies]
 focus-json.workspace = true
-tokio = { workspace = true, features = ["rt", "net", "io-util", "sync"] }
+tokio = { workspace = true, features = ["net", "io-util", "time"] }
 rustls.workspace = true
 tokio-rustls.workspace = true
 rustls-native-certs.workspace = true
diff --git a/crates/focus-tui/src/app.rs b/crates/focus-tui/src/app.rs
index 0d7caf5..a51c008 100644
--- a/crates/focus-tui/src/app.rs
+++ b/crates/focus-tui/src/app.rs
@@ -918,14 +918,6 @@ impl App {
         }
     }
 
-    /// 把输入框的滚动对齐到底部（跟随模式）。
-    /// Align the scroll to the bottom when following.
-    pub fn clamp_scroll(&mut self) {
-        if self.follow {
-            self.scroll = self.max_scroll();
-        }
-    }
-
     /// 最大滚动偏移（由最近渲染的总行数决定；几何只含可展开块，不能用作依据）。
     /// Max scroll offset (based on the last render's total line count; the
     /// geometry only covers expandable blocks and is unusable for this).
diff --git a/crates/focus-tui/src/job.rs b/crates/focus-tui/src/job.rs
index 3c1d1b6..191dd73 100644
--- a/crates/focus-tui/src/job.rs
+++ b/crates/focus-tui/src/job.rs
@@ -113,6 +113,10 @@ fn run_job(job: RunJob, tx: Sender<JobEvent>) {
         if let Some(plan) =
             plan_compaction(&transcript, window, COMPACT_THRESHOLD, DEFAULT_KEEP_RATIO)
         {
+            let _ = tx.send(JobEvent::Note(format!(
+                "compacting… ({})",
+                focus_harness::compaction::describe_plan(&plan)
+            )));
             match summarize(provider.as_ref(), &job.config, &plan) {
                 Ok(summary) => {
                     transcript = apply_summary(&summary, &plan);
diff --git a/crates/focus-tui/src/ui.rs b/crates/focus-tui/src/ui.rs
index ecd578b..864b512 100644
--- a/crates/focus-tui/src/ui.rs
+++ b/crates/focus-tui/src/ui.rs
@@ -518,7 +518,8 @@ focus — 终端编码 agent
   /help      本帮助
 
 思考块与工具调用默认折叠，只显示摘要（耗时 / 内容）；
-点击或 Tab 可查看完整细节。";
+点击或 Tab 展开：第一次显示预览（剩余行数提示），再次展开显示全部；
+工具块把请求参数与执行结果合并展示。";
 
 fn draw_help_modal(frame: &mut Frame, area: Rect) {
     let rect = centered_rect(70, 70, area);