feat(effort): 实现 EffortPanel 组件主体（渲染 + 键盘交互 + 确认/取消分支）

- 横向 slider 布局：Faster ↔ Smarter 两极，6 档刻度
- useKeybindings 注册 EffortPanel context（←/→/h/l/home/end/enter/escape/q/ctrl+c）
- Enter 在 5 档之一 → 调 executeEffort 写 settings + AppState
- Enter 在 ultracode → 输出引导文案，不写状态
- Esc/q → "Effort unchanged."
- env override 时顶部黄色警告
- computeConfirmOutcome 注入 ApplyFn，便于测试（Task 5 补测试）

Co-Authored-By: glm-5.2 <zai-org@claude-code-best.win>

src/components/EffortPanel/EffortPanel.tsx

@@ -0,0 +1,110 @@
+import * as React from 'react';
+import { Box, Text } from '@anthropic/ink';
+import { useKeybindings } from '../../keybindings/useKeybinding.js';
+import { type EffortValue, getDisplayedEffortLevel, getEffortEnvOverride } from '../../utils/effort.js';
+import {
+  type PanelPosition,
+  CANCEL_MESSAGE,
+  computeConfirmOutcome,
+  getInitialCursor,
+  moveLeft,
+  moveRight,
+  PANEL_POSITIONS,
+} from './effortPanelState.js';
+import { executeEffort } from '../../commands/effort/effort.js';
+import { useMainLoopModel } from '../../hooks/useMainLoopModel.js';
+import { useSetAppState } from '../../state/AppState.js';
+
+// 终端 ≥ 80 cols 时使用；窄屏适配第二阶段处理
+const PANEL_WIDTH = 76;
+const SUBLABEL_ULTRACODE = 'xhigh + workflows';
+
+type Props = {
+  appStateEffort: EffortValue | undefined;
+  onDone: (message: string) => void;
+};
+
+// ▲ 落在每档中心列：均匀分布
+function cursorColumn(cursor: PanelPosition): number {
+  const segment = Math.floor(PANEL_WIDTH / PANEL_POSITIONS.length);
+  const idx = PANEL_POSITIONS.indexOf(cursor);
+  return segment * idx + Math.floor(segment / 2);
+}
+
+function renderPaddedLine(cursor: PanelPosition): string {
+  const col = cursorColumn(cursor);
+  // ▲ 上方的"分隔线 + 光标"行：左侧 ─，到列处 ▲，右侧继续 ─
+  return `${'─'.repeat(col)}▲${'─'.repeat(Math.max(0, PANEL_WIDTH - col - 1))}`;
+}
+
+export function EffortPanel({ appStateEffort, onDone }: Props): React.ReactNode {
+  const setAppState = useSetAppState();
+  const model = useMainLoopModel();
+
+  const envOverride = getEffortEnvOverride();
+  const displayed = getDisplayedEffortLevel(model, appStateEffort);
+  const initialCursor = getInitialCursor({ envOverride, appStateEffort, displayed });
+
+  const [cursor, setCursor] = React.useState<PanelPosition>(initialCursor);
+  const [done, setDone] = React.useState(false);
+
+  const handleConfirm = React.useCallback(() => {
+    if (done) return;
+    setDone(true);
+    const outcome = computeConfirmOutcome(cursor, executeEffort);
+    if (outcome.kind === 'apply' && outcome.effortUpdate) {
+      setAppState(prev => ({
+        ...prev,
+        effortValue: outcome.effortUpdate!.value,
+      }));
+    }
+    onDone(outcome.message);
+  }, [cursor, done, onDone, setAppState]);
+
+  const handleCancel = React.useCallback(() => {
+    if (done) return;
+    setDone(true);
+    onDone(CANCEL_MESSAGE);
+  }, [done, onDone]);
+
+  useKeybindings(
+    {
+      'effortPanel:decrease': () => setCursor(c => moveLeft(c)),
+      'effortPanel:increase': () => setCursor(c => moveRight(c)),
+      'effortPanel:home': () => setCursor('low'),
+      'effortPanel:end': () => setCursor('ultracode'),
+      'effortPanel:confirm': handleConfirm,
+      'effortPanel:cancel': handleCancel,
+    },
+    { context: 'EffortPanel' },
+  );
+
+  const envActive = envOverride !== null && envOverride !== undefined;
+  const envRaw = process.env.CLAUDE_CODE_EFFORT_LEVEL;
+
+  // 两极文字行：左 Faster + 中间空格 + 右 Smarter
+  const fasterLen = 'Faster'.length;
+  const smarterLen = 'Smarter'.length;
+  const gap = Math.max(0, PANEL_WIDTH - fasterLen - smarterLen);
+  const poleLine = `Faster${' '.repeat(gap)}Smarter`;
+
+  return (
+    <Box flexDirection="column" paddingX={1}>
+      <Text bold>Effort</Text>
+      {envActive && <Text color="ansi:yellow">{`⚠ CLAUDE_CODE_EFFORT_LEVEL=${envRaw} overrides this session`}</Text>}
+      <Box marginTop={1}>
+        <Text>{poleLine}</Text>
+      </Box>
+      <Text>{renderPaddedLine(cursor)}</Text>
+      <Text>
+        {PANEL_POSITIONS.map(p => (p as string).padEnd(11))
+          .join('')
+          .trimEnd()}
+      </Text>
+      <Text dimColor>{`${' '.repeat(Math.max(0, PANEL_WIDTH - SUBLABEL_ULTRACODE.length))}${SUBLABEL_ULTRACODE}`}</Text>
+      <Box marginTop={1}>
+        <Text dimColor>←/→ adjust · Enter confirm · Esc cancel</Text>
+      </Box>
+    </Box>
+  );
+}