feat: 12 UX commands - brief, vim, theme, usage, tips, env, perf, etc (Phase 4B)

New commands:
- /brief: toggle concise output mode
- /vim: toggle vi-mode editing
- /theme: switch color theme (dark/light/auto)
- /usage: detailed token/cost breakdown with visual bar
- /tips: usage tips (random or /tips all)
- /output-style: output format (markdown/plain/json)
- /env: environment variables, config paths, system info
- /performance (/perf): memory, threads, GC, session metrics
- /privacy: telemetry/logging/memory opt-out settings
- /feedback: save feedback to ~/.claude-code-java/feedback/
- /release-notes (/changelog): version history
- /keybindings (/keys): keyboard shortcuts reference

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

src/main/java/com/claudecode/command/impl/BriefCommand.java

@@ -0,0 +1,40 @@
+package com.claudecode.command.impl;
+
+import com.claudecode.command.CommandContext;
+import com.claudecode.command.SlashCommand;
+import com.claudecode.console.AnsiStyle;
+
+/**
+ * /brief 命令 —— 切换简洁输出模式。
+ */
+public class BriefCommand implements SlashCommand {
+
+    @Override
+    public String name() { return "brief"; }
+
+    @Override
+    public String description() { return "Toggle brief output mode"; }
+
+    @Override
+    public String execute(String args, CommandContext context) {
+        if (context.agentLoop() == null) {
+            return AnsiStyle.red("  ✗ No active session");
+        }
+
+        var toolCtx = context.agentLoop().getToolContext();
+        boolean current = Boolean.TRUE.equals(toolCtx.get("BRIEF_MODE"));
+
+        String trimmed = (args == null) ? "" : args.trim();
+        boolean newMode = switch (trimmed) {
+            case "on", "enable", "true" -> true;
+            case "off", "disable", "false" -> false;
+            default -> !current; // toggle
+        };
+
+        toolCtx.set("BRIEF_MODE", newMode);
+
+        return newMode
+                ? AnsiStyle.green("  ✓ Brief mode ON") + " — responses will be concise"
+                : AnsiStyle.green("  ✓ Brief mode OFF") + " — responses will be detailed";
+    }
+}

src/main/java/com/claudecode/command/impl/EnvCommand.java

@@ -0,0 +1,93 @@
+package com.claudecode.command.impl;
+
+import com.claudecode.command.CommandContext;
+import com.claudecode.command.SlashCommand;
+import com.claudecode.console.AnsiStyle;
+
+import java.io.File;
+import java.lang.management.ManagementFactory;
+import java.util.List;
+import java.util.Map;
+import java.util.TreeMap;
+
+/**
+ * /env 命令 —— 显示环境变量和配置信息。
+ */
+public class EnvCommand implements SlashCommand {
+
+    @Override
+    public String name() { return "env"; }
+
+    @Override
+    public String description() { return "Show environment variables and configuration"; }
+
+    @Override
+    public String execute(String args, CommandContext context) {
+        String trimmed = (args == null) ? "" : args.trim();
+
+        StringBuilder sb = new StringBuilder();
+        sb.append("\n").append(AnsiStyle.bold("  🔧 Environment\n"));
+        sb.append("  ").append("─".repeat(50)).append("\n\n");
+
+        // System info
+        sb.append(AnsiStyle.bold("  System\n"));
+        sb.append("  OS:       ").append(System.getProperty("os.name")).append(" ")
+                .append(System.getProperty("os.version")).append("\n");
+        sb.append("  Java:     ").append(System.getProperty("java.version"))
+                .append(" (").append(System.getProperty("java.vendor")).append(")\n");
+        sb.append("  JVM:      ").append(System.getProperty("java.vm.name")).append("\n");
+        sb.append("  Heap:     ").append(formatBytes(Runtime.getRuntime().totalMemory()))
+                .append(" / ").append(formatBytes(Runtime.getRuntime().maxMemory())).append("\n");
+        sb.append("  PID:      ").append(ProcessHandle.current().pid()).append("\n\n");
+
+        // Work directory
+        sb.append(AnsiStyle.bold("  Paths\n"));
+        sb.append("  WorkDir:  ").append(System.getProperty("user.dir")).append("\n");
+        sb.append("  Home:     ").append(System.getProperty("user.home")).append("\n");
+        sb.append("  Config:   ").append(System.getProperty("user.home"))
+                .append(File.separator).append(".claude-code-java").append("\n\n");
+
+        // Relevant env vars
+        sb.append(AnsiStyle.bold("  Environment Variables\n"));
+        List<String> relevantVars = List.of(
+                "ANTHROPIC_API_KEY", "OPENAI_API_KEY", "CLAUDE_CODE_",
+                "JAVA_HOME", "PATH", "SHELL", "TERM", "EDITOR"
+        );
+
+        Map<String, String> env = new TreeMap<>(System.getenv());
+        for (Map.Entry<String, String> entry : env.entrySet()) {
+            String key = entry.getKey();
+            boolean show = false;
+            for (String prefix : relevantVars) {
+                if (key.startsWith(prefix) || key.equals(prefix)) {
+                    show = true;
+                    break;
+                }
+            }
+            if (!show && !trimmed.equals("all")) continue;
+
+            String value = entry.getValue();
+            // Mask secrets
+            if (key.contains("KEY") || key.contains("SECRET") || key.contains("TOKEN")) {
+                value = value.length() > 8 ? value.substring(0, 4) + "****" + value.substring(value.length() - 4) : "****";
+            }
+            // Truncate long values
+            if (value.length() > 80) {
+                value = value.substring(0, 77) + "...";
+            }
+            sb.append("  ").append(AnsiStyle.cyan(key)).append("=").append(value).append("\n");
+        }
+
+        if (!trimmed.equals("all")) {
+            sb.append("\n").append(AnsiStyle.dim("  Run /env all to show all environment variables"));
+        }
+
+        return sb.toString();
+    }
+
+    private String formatBytes(long bytes) {
+        if (bytes >= 1_073_741_824) return String.format("%.1fGB", bytes / 1_073_741_824.0);
+        if (bytes >= 1_048_576) return String.format("%.0fMB", bytes / 1_048_576.0);
+        return String.format("%.0fKB", bytes / 1_024.0);
+    }
+}

src/main/java/com/claudecode/command/impl/FeedbackCommand.java

@@ -0,0 +1,56 @@
+package com.claudecode.command.impl;
+
+import com.claudecode.command.CommandContext;
+import com.claudecode.command.SlashCommand;
+import com.claudecode.console.AnsiStyle;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.time.Instant;
+
+/**
+ * /feedback 命令 —— 提交反馈（本地保存）。
+ */
+public class FeedbackCommand implements SlashCommand {
+
+    @Override
+    public String name() { return "feedback"; }
+
+    @Override
+    public String description() { return "Submit feedback (saved locally)"; }
+
+    @Override
+    public String execute(String args, CommandContext context) {
+        String trimmed = (args == null) ? "" : args.trim();
+
+        if (trimmed.isEmpty()) {
+            return AnsiStyle.yellow("  Usage: /feedback <your feedback text>")
+                    + "\n" + AnsiStyle.dim("  Feedback is saved locally to ~/.claude-code-java/feedback/");
+        }
+
+        try {
+            Path feedbackDir = Path.of(System.getProperty("user.home"),
+                    ".claude-code-java", "feedback");
+            Files.createDirectories(feedbackDir);
+
+            String timestamp = Instant.now().toString().replaceAll("[:]", "-");
+            Path feedbackFile = feedbackDir.resolve("feedback-" + timestamp + ".txt");
+
+            StringBuilder content = new StringBuilder();
+            content.append("Timestamp: ").append(Instant.now()).append("\n");
+            content.append("OS: ").append(System.getProperty("os.name")).append("\n");
+            content.append("Java: ").append(System.getProperty("java.version")).append("\n");
+            content.append("WorkDir: ").append(System.getProperty("user.dir")).append("\n");
+            content.append("---\n");
+            content.append(trimmed).append("\n");
+
+            Files.writeString(feedbackFile, content.toString());
+
+            return AnsiStyle.green("  ✓ Feedback saved: " + feedbackFile.getFileName())
+                    + "\n" + AnsiStyle.dim("  Thank you for your feedback!");
+        } catch (IOException e) {
+            return AnsiStyle.red("  ✗ Failed to save feedback: " + e.getMessage());
+        }
+    }
+}

src/main/java/com/claudecode/command/impl/KeybindingsCommand.java

@@ -0,0 +1,60 @@
+package com.claudecode.command.impl;
+
+import com.claudecode.command.CommandContext;
+import com.claudecode.command.SlashCommand;
+import com.claudecode.console.AnsiStyle;
+
+import java.util.List;
+
+/**
+ * /keybindings 命令 —— 显示和配置快捷键。
+ */
+public class KeybindingsCommand implements SlashCommand {
+
+    @Override
+    public String name() { return "keybindings"; }
+
+    @Override
+    public String description() { return "Show keyboard shortcuts"; }
+
+    @Override
+    public List<String> aliases() {
+        return List.of("keys", "shortcuts");
+    }
+
+    @Override
+    public String execute(String args, CommandContext context) {
+        StringBuilder sb = new StringBuilder();
+        sb.append("\n").append(AnsiStyle.bold("  ⌨️  Keyboard Shortcuts\n"));
+        sb.append("  ").append("─".repeat(50)).append("\n\n");
+
+        sb.append(AnsiStyle.bold("  Input\n"));
+        sb.append("  ").append(AnsiStyle.cyan("Enter        ")).append(" Submit message\n");
+        sb.append("  ").append(AnsiStyle.cyan("Shift+Enter  ")).append(" New line\n");
+        sb.append("  ").append(AnsiStyle.cyan("Tab          ")).append(" Command completion\n");
+        sb.append("  ").append(AnsiStyle.cyan("↑/↓          ")).append(" History navigation\n");
+        sb.append("  ").append(AnsiStyle.cyan("Ctrl+A       ")).append(" Move to line start\n");
+        sb.append("  ").append(AnsiStyle.cyan("Ctrl+E       ")).append(" Move to line end\n");
+        sb.append("  ").append(AnsiStyle.cyan("Ctrl+W       ")).append(" Delete word backward\n");
+        sb.append("  ").append(AnsiStyle.cyan("Ctrl+U       ")).append(" Delete to line start\n");
+        sb.append("  ").append(AnsiStyle.cyan("Ctrl+K       ")).append(" Delete to line end\n\n");
+
+        sb.append(AnsiStyle.bold("  Control\n"));
+        sb.append("  ").append(AnsiStyle.cyan("Ctrl+C       ")).append(" Interrupt current operation\n");
+        sb.append("  ").append(AnsiStyle.cyan("Ctrl+D       ")).append(" Exit (when input is empty)\n");
+        sb.append("  ").append(AnsiStyle.cyan("Ctrl+L       ")).append(" Clear screen\n");
+        sb.append("  ").append(AnsiStyle.cyan("Ctrl+R       ")).append(" Reverse history search\n\n");
+
+        sb.append(AnsiStyle.bold("  Vim Mode (/vim to enable)\n"));
+        sb.append("  ").append(AnsiStyle.cyan("Esc          ")).append(" Normal mode\n");
+        sb.append("  ").append(AnsiStyle.cyan("i            ")).append(" Insert mode\n");
+        sb.append("  ").append(AnsiStyle.cyan("a            ")).append(" Append after cursor\n");
+        sb.append("  ").append(AnsiStyle.cyan("dd           ")).append(" Delete line\n");
+        sb.append("  ").append(AnsiStyle.cyan("yy           ")).append(" Yank line\n");
+        sb.append("  ").append(AnsiStyle.cyan("p            ")).append(" Paste\n");
+        sb.append("  ").append(AnsiStyle.cyan("w/b          ")).append(" Word forward/backward\n");
+        sb.append("  ").append(AnsiStyle.cyan("0/$          ")).append(" Line start/end\n");
+
+        return sb.toString();
+    }
+}

src/main/java/com/claudecode/command/impl/OutputStyleCommand.java

@@ -0,0 +1,49 @@
+package com.claudecode.command.impl;
+
+import com.claudecode.command.CommandContext;
+import com.claudecode.command.SlashCommand;
+import com.claudecode.console.AnsiStyle;
+
+/**
+ * /output-style 命令 —— 输出风格设置。
+ */
+public class OutputStyleCommand implements SlashCommand {
+
+    @Override
+    public String name() { return "output-style"; }
+
+    @Override
+    public String description() { return "Set output format (markdown/plain/json)"; }
+
+    @Override
+    public String execute(String args, CommandContext context) {
+        if (context.agentLoop() == null) {
+            return AnsiStyle.red("  ✗ No active session");
+        }
+
+        var toolCtx = context.agentLoop().getToolContext();
+        String current = (String) toolCtx.get("OUTPUT_STYLE");
+        if (current == null) current = "markdown";
+
+        String trimmed = (args == null) ? "" : args.trim().toLowerCase();
+
+        if (trimmed.isEmpty()) {
+            return "\n" + AnsiStyle.bold("  📝 Output Style\n")
+                    + "  " + "─".repeat(30) + "\n\n"
+                    + "  Current: " + AnsiStyle.cyan(current) + "\n\n"
+                    + "  Options:\n"
+                    + "    " + AnsiStyle.bold("markdown") + " — Rich formatting with code blocks\n"
+                    + "    " + AnsiStyle.bold("plain") + "    — Plain text, no formatting\n"
+                    + "    " + AnsiStyle.bold("json") + "     — JSON structured output\n"
+                    + "\n" + AnsiStyle.dim("  Usage: /output-style <markdown|plain|json>");
+        }
+
+        if (!trimmed.equals("markdown") && !trimmed.equals("plain") && !trimmed.equals("json")) {
+            return AnsiStyle.yellow("  Unknown style: " + trimmed)
+                    + "\n" + AnsiStyle.dim("  Options: markdown, plain, json");
+        }
+
+        toolCtx.set("OUTPUT_STYLE", trimmed);
+        return AnsiStyle.green("  ✓ Output style set to " + trimmed);
+    }
+}

src/main/java/com/claudecode/command/impl/PerformanceCommand.java

@@ -0,0 +1,104 @@
+package com.claudecode.command.impl;
+
+import com.claudecode.command.CommandContext;
+import com.claudecode.command.SlashCommand;
+import com.claudecode.console.AnsiStyle;
+import com.claudecode.telemetry.MetricsCollector;
+
+/**
+ * /performance 命令 —— 性能统计。
+ */
+public class PerformanceCommand implements SlashCommand {
+
+    @Override
+    public String name() { return "performance"; }
+
+    @Override
+    public String description() { return "Show performance statistics"; }
+
+    @Override
+    public java.util.List<String> aliases() {
+        return java.util.List.of("perf");
+    }
+
+    @Override
+    public String execute(String args, CommandContext context) {
+        StringBuilder sb = new StringBuilder();
+        sb.append("\n").append(AnsiStyle.bold("  ⚡ Performance Statistics\n"));
+        sb.append("  ").append("─".repeat(40)).append("\n\n");
+
+        // JVM stats
+        Runtime runtime = Runtime.getRuntime();
+        long totalMem = runtime.totalMemory();
+        long freeMem = runtime.freeMemory();
+        long usedMem = totalMem - freeMem;
+        long maxMem = runtime.maxMemory();
+
+        sb.append(AnsiStyle.bold("  Memory\n"));
+        sb.append("  Used:      ").append(formatBytes(usedMem)).append("\n");
+        sb.append("  Allocated: ").append(formatBytes(totalMem)).append("\n");
+        sb.append("  Max:       ").append(formatBytes(maxMem)).append("\n");
+        sb.append("  Usage:     ").append(memBar(usedMem, maxMem)).append("\n\n");
+
+        // Thread stats
+        int threadCount = Thread.activeCount();
+        sb.append(AnsiStyle.bold("  Threads\n"));
+        sb.append("  Active:    ").append(threadCount).append("\n");
+        sb.append("  Available: ").append(runtime.availableProcessors()).append(" CPUs\n\n");
+
+        // GC stats
+        long gcCount = 0;
+        long gcTime = 0;
+        for (var gc : java.lang.management.ManagementFactory.getGarbageCollectorMXBeans()) {
+            gcCount += gc.getCollectionCount();
+            gcTime += gc.getCollectionTime();
+        }
+        sb.append(AnsiStyle.bold("  GC\n"));
+        sb.append("  Collections: ").append(gcCount).append("\n");
+        sb.append("  Total time:  ").append(gcTime).append("ms\n\n");
+
+        // Metrics if available
+        if (context.agentLoop() != null) {
+            Object metricsObj = context.agentLoop().getToolContext().get("METRICS_COLLECTOR");
+            if (metricsObj instanceof MetricsCollector metrics) {
+                sb.append(AnsiStyle.bold("  Session Metrics\n"));
+                sb.append("  Duration:    ").append(formatDuration(metrics.getSessionDurationSeconds())).append("\n");
+                var toolUsage = metrics.getToolUsage();
+                if (!toolUsage.isEmpty()) {
+                    sb.append("  Tool calls:  ").append(toolUsage.values().stream().mapToLong(Long::longValue).sum()).append("\n");
+                    sb.append("  Top tools:   ");
+                    toolUsage.entrySet().stream()
+                            .sorted(java.util.Map.Entry.<String, Long>comparingByValue().reversed())
+                            .limit(3)
+                            .forEach(e -> sb.append(e.getKey()).append("(").append(e.getValue()).append(") "));
+                    sb.append("\n");
+                }
+            }
+        }
+
+        return sb.toString();
+    }
+
+    private String memBar(long used, long max) {
+        int barWidth = 20;
+        double ratio = (double) used / max;
+        int filled = (int) (ratio * barWidth);
+        String color = ratio > 0.8 ? AnsiStyle.red("█".repeat(filled))
+                : ratio > 0.5 ? AnsiStyle.yellow("█".repeat(filled))
+                : AnsiStyle.green("█".repeat(filled));
+        return "[" + color + "░".repeat(barWidth - filled) + "] " +
+                String.format("%.0f%%", ratio * 100);
+    }
+
+    private String formatBytes(long bytes) {
+        if (bytes >= 1_073_741_824) return String.format("%.1fGB", bytes / 1_073_741_824.0);
+        if (bytes >= 1_048_576) return String.format("%.0fMB", bytes / 1_048_576.0);
+        return String.format("%.0fKB", bytes / 1_024.0);
+    }
+
+    private String formatDuration(long seconds) {
+        if (seconds < 60) return seconds + "s";
+        if (seconds < 3600) return (seconds / 60) + "m " + (seconds % 60) + "s";
+        return (seconds / 3600) + "h " + ((seconds % 3600) / 60) + "m";
+    }
+}

src/main/java/com/claudecode/command/impl/PrivacyCommand.java

@@ -0,0 +1,70 @@
+package com.claudecode.command.impl;
+
+import com.claudecode.command.CommandContext;
+import com.claudecode.command.SlashCommand;
+import com.claudecode.console.AnsiStyle;
+
+/**
+ * /privacy 命令 —— 隐私设置查看和修改。
+ */
+public class PrivacyCommand implements SlashCommand {
+
+    @Override
+    public String name() { return "privacy"; }
+
+    @Override
+    public String description() { return "View/modify privacy settings"; }
+
+    @Override
+    public String execute(String args, CommandContext context) {
+        if (context.agentLoop() == null) {
+            return AnsiStyle.red("  ✗ No active session");
+        }
+
+        var toolCtx = context.agentLoop().getToolContext();
+        boolean telemetryEnabled = Boolean.TRUE.equals(toolCtx.get("TELEMETRY_ENABLED"));
+        boolean sessionLogging = !Boolean.FALSE.equals(toolCtx.get("SESSION_LOGGING"));
+        boolean memoryPersist = !Boolean.FALSE.equals(toolCtx.get("MEMORY_PERSIST"));
+
+        String trimmed = (args == null) ? "" : args.trim().toLowerCase();
+
+        if (trimmed.isEmpty()) {
+            StringBuilder sb = new StringBuilder();
+            sb.append("\n").append(AnsiStyle.bold("  🔒 Privacy Settings\n"));
+            sb.append("  ").append("─".repeat(40)).append("\n\n");
+            sb.append("  ").append(statusIcon(telemetryEnabled)).append(" Telemetry:        ")
+                    .append(telemetryEnabled ? "Enabled" : "Disabled").append("\n");
+            sb.append("  ").append(statusIcon(sessionLogging)).append(" Session Logging:  ")
+                    .append(sessionLogging ? "Enabled" : "Disabled").append("\n");
+            sb.append("  ").append(statusIcon(memoryPersist)).append(" Memory Persist:   ")
+                    .append(memoryPersist ? "Enabled" : "Disabled").append("\n");
+            sb.append("\n").append(AnsiStyle.dim("  Toggle: /privacy <telemetry|logging|memory> <on|off>"));
+            return sb.toString();
+        }
+
+        String[] parts = trimmed.split("\\s+", 2);
+        String setting = parts[0];
+        boolean enable = parts.length > 1 && ("on".equals(parts[1]) || "enable".equals(parts[1]) || "true".equals(parts[1]));
+
+        return switch (setting) {
+            case "telemetry" -> {
+                toolCtx.set("TELEMETRY_ENABLED", enable);
+                yield AnsiStyle.green("  ✓ Telemetry " + (enable ? "enabled" : "disabled"));
+            }
+            case "logging" -> {
+                toolCtx.set("SESSION_LOGGING", enable);
+                yield AnsiStyle.green("  ✓ Session logging " + (enable ? "enabled" : "disabled"));
+            }
+            case "memory" -> {
+                toolCtx.set("MEMORY_PERSIST", enable);
+                yield AnsiStyle.green("  ✓ Memory persistence " + (enable ? "enabled" : "disabled"));
+            }
+            default -> AnsiStyle.yellow("  Unknown setting: " + setting)
+                    + "\n" + AnsiStyle.dim("  Options: telemetry, logging, memory");
+        };
+    }
+
+    private String statusIcon(boolean enabled) {
+        return enabled ? AnsiStyle.green("●") : AnsiStyle.red("○");
+    }
+}

src/main/java/com/claudecode/command/impl/ReleaseNotesCommand.java

@@ -0,0 +1,66 @@
+package com.claudecode.command.impl;
+
+import com.claudecode.command.CommandContext;
+import com.claudecode.command.SlashCommand;
+import com.claudecode.console.AnsiStyle;
+
+import java.util.List;
+
+/**
+ * /release-notes 命令 —— 显示版本更新日志。
+ */
+public class ReleaseNotesCommand implements SlashCommand {
+
+    @Override
+    public String name() { return "release-notes"; }
+
+    @Override
+    public String description() { return "Show version release notes"; }
+
+    @Override
+    public List<String> aliases() {
+        return List.of("changelog", "whatsnew");
+    }
+
+    @Override
+    public String execute(String args, CommandContext context) {
+        StringBuilder sb = new StringBuilder();
+        sb.append("\n").append(AnsiStyle.bold("  📋 Release Notes\n"));
+        sb.append("  ").append("─".repeat(50)).append("\n\n");
+
+        sb.append(AnsiStyle.bold("  v0.4.0 — Phase 4: Commands, Tools & Services\n"));
+        sb.append("  ").append("─".repeat(45)).append("\n");
+        sb.append("  • LSPTool: code navigation via Language Server Protocol\n");
+        sb.append("  • BriefTool: output verbosity control\n");
+        sb.append("  • NotificationTool: cross-platform desktop notifications\n");
+        sb.append("  • 12 new commands: /brief, /vim, /theme, /usage, /tips, etc.\n");
+        sb.append("  • RateLimiter, TokenEstimation, InternalLogger services\n");
+        sb.append("  • Debug commands: /debug, /heapdump, /trace, /ctx-viz\n\n");
+
+        sb.append(AnsiStyle.bold("  v0.3.0 — Phase 3: Advanced Infrastructure\n"));
+        sb.append("  ").append("─".repeat(45)).append("\n");
+        sb.append("  • Server Mode: WebSocket direct connect for SDK integration\n");
+        sb.append("  • Git Worktree: parallel branch isolation for agent tasks\n");
+        sb.append("  • LSP Integration: JSON-RPC client, multi-server, diagnostics\n");
+        sb.append("  • Telemetry: Feature flags, metrics, feature gates\n");
+        sb.append("  • Plugin Marketplace: install, search, auto-update plugins\n\n");
+
+        sb.append(AnsiStyle.bold("  v0.2.0 — Phase 2: Core Features\n"));
+        sb.append("  ").append("─".repeat(45)).append("\n");
+        sb.append("  • Plan Mode for multi-step task planning\n");
+        sb.append("  • Skills execution system with /skill command\n");
+        sb.append("  • Session Memory with CLAUDE.md auto-persist\n");
+        sb.append("  • Coordinator Mode with multi-agent messaging\n");
+        sb.append("  • MCP enhancements: HTTP+SSE, resources, env vars\n\n");
+
+        sb.append(AnsiStyle.bold("  v0.1.0 — Phase 1: Foundation\n"));
+        sb.append("  ").append("─".repeat(45)).append("\n");
+        sb.append("  • Enhanced system prompts (7 security/style sections)\n");
+        sb.append("  • 8 tool description improvements\n");
+        sb.append("  • New tools: TaskStop, TaskOutput, Sleep, ToolSearch\n");
+        sb.append("  • Command enhancements: /help search, /compact stats\n");
+        sb.append("  • UI: markdown tables, spinner styles, tool status\n");
+
+        return sb.toString();
+    }
+}

src/main/java/com/claudecode/command/impl/ThemeCommand.java

@@ -0,0 +1,52 @@
+package com.claudecode.command.impl;
+
+import com.claudecode.command.CommandContext;
+import com.claudecode.command.SlashCommand;
+import com.claudecode.console.AnsiStyle;
+
+/**
+ * /theme 命令 —— 切换主题（dark/light/auto）。
+ */
+public class ThemeCommand implements SlashCommand {
+
+    @Override
+    public String name() { return "theme"; }
+
+    @Override
+    public String description() { return "Switch color theme (dark/light/auto)"; }
+
+    @Override
+    public String execute(String args, CommandContext context) {
+        if (context.agentLoop() == null) {
+            return AnsiStyle.red("  ✗ No active session");
+        }
+
+        var toolCtx = context.agentLoop().getToolContext();
+        String current = (String) toolCtx.get("THEME");
+        if (current == null) current = "dark";
+
+        String trimmed = (args == null) ? "" : args.trim().toLowerCase();
+
+        if (trimmed.isEmpty()) {
+            return "\n" + AnsiStyle.bold("  🎨 Theme Settings\n")
+                    + "  " + "─".repeat(30) + "\n\n"
+                    + "  Current: " + AnsiStyle.cyan(current) + "\n"
+                    + "  Options: " + AnsiStyle.dim("dark, light, auto") + "\n"
+                    + "\n" + AnsiStyle.dim("  Usage: /theme <dark|light|auto>");
+        }
+
+        if (!trimmed.equals("dark") && !trimmed.equals("light") && !trimmed.equals("auto")) {
+            return AnsiStyle.yellow("  Unknown theme: " + trimmed)
+                    + "\n" + AnsiStyle.dim("  Options: dark, light, auto");
+        }
+
+        toolCtx.set("THEME", trimmed);
+        String icon = switch (trimmed) {
+            case "dark" -> "🌙";
+            case "light" -> "☀️";
+            case "auto" -> "🔄";
+            default -> "🎨";
+        };
+        return AnsiStyle.green("  ✓ Theme set to " + trimmed + " " + icon);
+    }
+}

src/main/java/com/claudecode/command/impl/TipsCommand.java

@@ -0,0 +1,65 @@
+package com.claudecode.command.impl;
+
+import com.claudecode.command.CommandContext;
+import com.claudecode.command.SlashCommand;
+import com.claudecode.console.AnsiStyle;
+
+import java.util.List;
+import java.util.Random;
+
+/**
+ * /tips 命令 —— 显示使用技巧和建议。
+ */
+public class TipsCommand implements SlashCommand {
+
+    private static final List<String> TIPS = List.of(
+            "Use /compact when the conversation gets long to reduce token usage",
+            "Use /brief to toggle concise output mode for faster responses",
+            "Chain commands: 'run tests && fix any failures' lets the agent iterate",
+            "Use /plan to enter plan mode — great for complex multi-step tasks",
+            "Use /memory to save important context that persists across sessions",
+            "Press Ctrl+C to interrupt a long-running tool execution",
+            "Use /status to check token usage and session health",
+            "Use /commit --push to commit and push in one command",
+            "Agent tasks (/tasks) run in parallel — great for concurrent work",
+            "Use /vim to enable vi-mode editing in the input field",
+            "Use /theme to switch between dark and light themes",
+            "Use /diff to review uncommitted changes before committing",
+            "CLAUDE.md files in your project root customize agent behavior",
+            "Use /skills to discover and load skill templates",
+            "Use /plugin search to find community plugins",
+            "Use /export to save the conversation as markdown",
+            "Use /usage to see detailed token and cost breakdown",
+            "Use /doctor to diagnose configuration issues",
+            "Use /context to see what files are loaded in context",
+            "Use /keybindings to see all keyboard shortcuts"
+    );
+
+    private final Random random = new Random();
+
+    @Override
+    public String name() { return "tips"; }
+
+    @Override
+    public String description() { return "Show usage tips and suggestions"; }
+
+    @Override
+    public String execute(String args, CommandContext context) {
+        String trimmed = (args == null) ? "" : args.trim();
+
+        if ("all".equals(trimmed)) {
+            StringBuilder sb = new StringBuilder();
+            sb.append("\n").append(AnsiStyle.bold("  💡 All Tips\n"));
+            sb.append("  ").append("─".repeat(50)).append("\n\n");
+            for (int i = 0; i < TIPS.size(); i++) {
+                sb.append(String.format("  %2d. %s%n", i + 1, TIPS.get(i)));
+            }
+            return sb.toString();
+        }
+
+        // Show random tip
+        String tip = TIPS.get(random.nextInt(TIPS.size()));
+        return "\n  💡 " + AnsiStyle.bold("Tip: ") + tip + "\n\n"
+                + AnsiStyle.dim("  Run /tips all to see all tips");
+    }
+}

src/main/java/com/claudecode/command/impl/UsageCommand.java

@@ -0,0 +1,71 @@
+package com.claudecode.command.impl;
+
+import com.claudecode.command.CommandContext;
+import com.claudecode.command.SlashCommand;
+import com.claudecode.console.AnsiStyle;
+import com.claudecode.core.TokenTracker;
+
+/**
+ * /usage 命令 —— 详细 token 和费用统计。
+ */
+public class UsageCommand implements SlashCommand {
+
+    @Override
+    public String name() { return "usage"; }
+
+    @Override
+    public String description() { return "Show detailed token usage and cost breakdown"; }
+
+    @Override
+    public String execute(String args, CommandContext context) {
+        if (context.agentLoop() == null) {
+            return AnsiStyle.red("  ✗ No active session");
+        }
+
+        TokenTracker tracker = context.agentLoop().getTokenTracker();
+
+        long inputTokens = tracker.getInputTokens();
+        long outputTokens = tracker.getOutputTokens();
+        long totalTokens = inputTokens + outputTokens;
+
+        // Approximate costs (Claude 3.5 Sonnet pricing)
+        double inputCost = inputTokens / 1_000_000.0 * 3.0;  // $3/M input
+        double outputCost = outputTokens / 1_000_000.0 * 15.0; // $15/M output
+        double totalCost = inputCost + outputCost;
+
+        StringBuilder sb = new StringBuilder();
+        sb.append("\n");
+        sb.append(AnsiStyle.bold("  📊 Token Usage & Cost\n"));
+        sb.append("  ").append("─".repeat(40)).append("\n\n");
+
+        sb.append("  ").append(AnsiStyle.bold("Model:          ")).append(AnsiStyle.cyan(tracker.getModelName())).append("\n\n");
+
+        sb.append("  ").append(AnsiStyle.bold("Input Tokens:   ")).append(formatNumber(inputTokens)).append("\n");
+        sb.append("  ").append(AnsiStyle.bold("Output Tokens:  ")).append(formatNumber(outputTokens)).append("\n");
+        sb.append("  ").append(AnsiStyle.bold("Total Tokens:   ")).append(formatNumber(totalTokens)).append("\n\n");
+
+        sb.append("  ").append(AnsiStyle.bold("Estimated Cost")).append("\n");
+        sb.append("  Input:  $").append(String.format("%.4f", inputCost)).append(" (").append(formatNumber(inputTokens)).append(" × $3/M)\n");
+        sb.append("  Output: $").append(String.format("%.4f", outputCost)).append(" (").append(formatNumber(outputTokens)).append(" × $15/M)\n");
+        sb.append("  ").append(AnsiStyle.bold("Total:  $" + String.format("%.4f", totalCost))).append("\n\n");
+
+        // Usage bar
+        if (totalTokens > 0) {
+            int barWidth = 30;
+            int inputBar = (int) ((double) inputTokens / totalTokens * barWidth);
+            int outputBar = barWidth - inputBar;
+            sb.append("  [").append(AnsiStyle.blue("█".repeat(inputBar)))
+                    .append(AnsiStyle.green("█".repeat(outputBar))).append("]\n");
+            sb.append("  ").append(AnsiStyle.blue("■")).append(" Input  ")
+                    .append(AnsiStyle.green("■")).append(" Output\n");
+        }
+
+        return sb.toString();
+    }
+
+    private String formatNumber(long n) {
+        if (n >= 1_000_000) return String.format("%.1fM", n / 1_000_000.0);
+        if (n >= 1_000) return String.format("%.1fK", n / 1_000.0);
+        return String.valueOf(n);
+    }
+}

src/main/java/com/claudecode/command/impl/VimCommand.java

@@ -0,0 +1,43 @@
+package com.claudecode.command.impl;
+
+import com.claudecode.command.CommandContext;
+import com.claudecode.command.SlashCommand;
+import com.claudecode.console.AnsiStyle;
+
+/**
+ * /vim 命令 —— 切换 Vi 编辑模式（JLine vi-mode）。
+ */
+public class VimCommand implements SlashCommand {
+
+    @Override
+    public String name() { return "vim"; }
+
+    @Override
+    public String description() { return "Toggle vim editing mode"; }
+
+    @Override
+    public String execute(String args, CommandContext context) {
+        if (context.agentLoop() == null) {
+            return AnsiStyle.red("  ✗ No active session");
+        }
+
+        var toolCtx = context.agentLoop().getToolContext();
+        boolean current = Boolean.TRUE.equals(toolCtx.get("VIM_MODE"));
+
+        String trimmed = (args == null) ? "" : args.trim();
+        boolean newMode = switch (trimmed) {
+            case "on", "enable" -> true;
+            case "off", "disable" -> false;
+            default -> !current;
+        };
+
+        toolCtx.set("VIM_MODE", newMode);
+
+        if (newMode) {
+            return AnsiStyle.green("  ✓ Vim mode ON") + "\n"
+                    + AnsiStyle.dim("  Key bindings: ESC → normal mode, i → insert, dd → delete line");
+        } else {
+            return AnsiStyle.green("  ✓ Vim mode OFF") + " — standard editing";
+        }
+    }
+}

src/main/java/com/claudecode/config/AppConfig.java

@@ -187,6 +187,19 @@ public class AppConfig {
                 new SessionCommand(),
                 new AgentCommand(),
                 new RenameCommand(),
+                // Phase 4B 命令
+                new BriefCommand(),
+                new VimCommand(),
+                new ThemeCommand(),
+                new UsageCommand(),
+                new TipsCommand(),
+                new OutputStyleCommand(),
+                new EnvCommand(),
+                new PerformanceCommand(),
+                new PrivacyCommand(),
+                new FeedbackCommand(),
+                new ReleaseNotesCommand(),
+                new KeybindingsCommand(),
                 // Exit 放最后
                 new ExitCommand()
         );