Wave 5+6: plugin ABI hardening, build modernization, ABI/security docs

Wave 5 (9 parallel agents):
- W1.1 atomic diag callback + DLL handle release on shutdown (lin)
- W2.1 unify cross-DLL heap discipline (host->alloc/free/strdup) (chen)
- W2.2 secure_zero api_key on shutdown for deepseek/anthropic (cao)
- W3 CMake modernization: target-based cxx_std_20, dstalk_boost_config
  INTERFACE lib, root-level RUNTIME_OUTPUT_DIRECTORY (hu)
- W4 GitHub Actions CI with dynamic Linux/Windows matrix (ma)
- W5.1 SSE buffer_body to cut peak memory ~67% on 32K streams (zhou)
- W6.1 LSP JSON-RPC frame parser hardened against header reordering (sun)
- W7 smoke test: copy plugin DLLs post-build + Boost.JSON src.hpp fix
  for full 9-plugin load coverage (wang)
- W8.1 README slimmed 398->92, Diataxis docs/ skeleton (deng)

Wave 6 (6 parallel agents):
- W9.1 docs/explanation: architecture + plugin-lifecycle (deng)
- W9.3 log credential leak audit (0 vulns, audit trail in
  docs/explanation/security-logging.md) (cao)
- W9.4 docs/reference/plugin-abi.md - 7-point ABI contract (lin)
- W9.6 CLI /history command + status integration (zhao)
- W9.8 plugin_loader fault tolerance: per-plugin failure no longer
  aborts dstalk_init (huang)
- W9.10 host_api unit tests: tests/host_api_test.cpp, 8 cases (liu)

CEO oversight (preexisting bugs fixed during Wave 5 verification):
- lsp_plugin.cpp:449 forward decl mismatch (int vs void)
- tools_plugin.cpp:109 missing forward decl

Multi-agent collaboration framework:
- agents/WORKFLOW.md: 6-stage protocol, two-tier governance,
  prompt template, technical constraints registry

Build: cmake --build 0 error / 0 warning. Tests: 2/2 100% pass.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

dstalk-cli/src/main.cpp

@@ -92,6 +92,7 @@ static void print_help()
     std::printf("  %s/file write <p> <c>%s    写入文件\n", CLR_YELLOW, CLR_RESET);
     std::printf("  %s/save <path>%s           保存会话\n", CLR_YELLOW, CLR_RESET);
     std::printf("  %s/load <path>%s           恢复会话\n", CLR_YELLOW, CLR_RESET);
+    std::printf("  %s/history [N]%s           查看会话历史（默认全部，可指定最近N条）\n", CLR_YELLOW, CLR_RESET);
     std::printf("\n直接输入问题即可与 AI 对话。\n\n");
 }
 
@@ -197,6 +198,9 @@ static void handle_command(const char* line)
         std::printf("  provider: %s\n", provider);
         std::printf("  AI 服务: %s\n", g_ai ? "就绪" : "不可用");
         std::printf("  Session 服务: %s\n", g_session ? "就绪" : "不可用");
+        int hc = 0;
+        if (g_session) g_session->history(&hc);
+        std::printf("  history count: %d\n", hc);
         std::printf("  File IO 服务: %s\n", g_file_io ? "就绪" : "不可用");
         const dstalk_tools_service_t* tools = static_cast<const dstalk_tools_service_t*>(
             dstalk_service_query("tools", 1));
@@ -261,6 +265,39 @@ static void handle_command(const char* line)
         return;
     }
 
+    // /history [N]
+    if (std::strcmp(line, "/history") == 0 || std::strncmp(line, "/history ", 9) == 0) {
+        if (!g_session) {
+            std::printf(CLR_RED "[ERROR] session service unavailable\n" CLR_RESET);
+            return;
+        }
+        int count = 0;
+        const dstalk_message_t* history = g_session->history(&count);
+        if (count == 0 || !history) {
+            std::printf(CLR_DIM "(history is empty)\n" CLR_RESET);
+            return;
+        }
+        int limit = count;
+        const char* arg = line + 8;
+        while (*arg == ' ') arg++;
+        if (*arg != '\0') {
+            char* end = nullptr;
+            long n = std::strtol(arg, &end, 10);
+            if (*end != '\0' || n <= 0) {
+                std::printf(CLR_RED "[ERROR] /history N: N must be a positive integer\n" CLR_RESET);
+                return;
+            }
+            limit = (n < count) ? static_cast<int>(n) : count;
+        }
+        int start = count - limit;
+        for (int i = start; i < count; i++) {
+            std::printf("[%s] %s\n",
+                        history[i].role ? history[i].role : "?",
+                        history[i].content ? history[i].content : "");
+        }
+        return;
+    }
+
     // /save <path>
     if (std::strncmp(line, "/save ", 6) == 0) {
         const char* path = line + 6;