Optimize startup, HTTP/SSE streaming, and fix macOS libedit bindings

bantam.hpp

@@ -138,6 +138,7 @@ struct Cfg {
   int force_stream = -1;   /* -1 = auto, 0/1 = force (compaction) */
   int context_window = 262144;
   int max_tool_res = 65536;
+  bool context_window_set = false;
   std::map<std::string, std::string> raw; /* raw key/value map */
 };
 
@@ -180,17 +181,48 @@ inline std::string cstr(std::string_view text, const R& codes) {
   s += "\033[";
   for (size_t i = 0; i < codes.size(); i++) {
     if (i) s += ';';
-    s += sfmt("%d", (int)codes[i]);
+    int v = (int)codes[i];
+    if (v <= 0) {
+      s += '0';
+    } else {
+      char rev[12];
+      int rn = 0;
+      while (v > 0 && rn < 12) { rev[rn++] = (char)('0' + (v % 10)); v /= 10; }
+      while (rn > 0) s += rev[--rn];
+    }
   }
-  s += "m";
+  s += 'm';
   s += text;
   s += "\033[0m";
   return s;
 }
 template<class R>
 inline void cprint(std::string_view text, const R& codes) {
-  std::string w = cstr(text, codes);
-  std::fputs(w.c_str(), stdout);
+  if (text.empty()) return;
+  if (!g_col || codes.empty()) {
+    std::fwrite(text.data(), 1, text.size(), stdout);
+    return;
+  }
+  char seq[32];
+  size_t pos = 0;
+  seq[pos++] = '\033';
+  seq[pos++] = '[';
+  for (size_t i = 0; i < codes.size() && pos + 12 < sizeof(seq); i++) {
+    if (i) seq[pos++] = ';';
+    int v = (int)codes[i];
+    if (v <= 0) {
+      seq[pos++] = '0';
+    } else {
+      char rev[12];
+      int rn = 0;
+      while (v > 0 && rn < 12) { rev[rn++] = (char)('0' + (v % 10)); v /= 10; }
+      while (rn > 0) seq[pos++] = rev[--rn];
+    }
+  }
+  seq[pos++] = 'm';
+  std::fwrite(seq, 1, pos, stdout);
+  std::fwrite(text.data(), 1, text.size(), stdout);
+  std::fwrite("\033[0m", 1, 4, stdout);
 }
 int visible_len(std::string_view s);
 int rune_width(int cp);
@@ -226,6 +258,7 @@ bool parse_nonstream_response(std::string_view body, Message &out, Usage &usage)
 /* ------------------------------------------------------------------ */
 /* llm.cpp — HTTP client (libcurl), headers, backoff, dispatch.        */
 /* ------------------------------------------------------------------ */
+void http_cleanup();
 int http_get(Cfg &cfg, std::string_view url, std::string &body, long &code,
              std::string &errmsg);
 int llm(Cfg &cfg, Messages &msgs, bool use_tools, Message &out, Usage &usage,