sessions: vault discovery tools, shared stdin, ctrl-key fixes

New sessions/session_export tools plus a sessions_block vault map in the system prompt (tai.py, ported to detz); recall/search carry a session footer instead of letting the model grep sealed bytes. write_file refuses new markdown at working/repo roots, and the blanket *.md gitignore is gone so docs stay visible. One LineInput owns fd 0 for every prompt (ask, approvals, shell_ask, secrets), ending phantom-empty answers; Ctrl-C re-prompts (double exits), Ctrl-D exits, Ctrl-Z suspends; mid-turn Ctrl-C announces itself and kills foreground shell children via RunInterrupted. Covered by SessionsTests, repl_keys.py pty checks, agent_diff sessions_block cases.

taicpp/src/shell/shellio.cpp

@@ -1,48 +1,24 @@
 #include "shellio.h"
 #include "ansi.h"
+#include "../repl/line_input.h"
 #include "../util/utf8.h"
 #include <cstdio>
-#include <fcntl.h>
-#include <iostream>
-#include <termios.h>
 #include <unistd.h>
 namespace detz::shell {
 namespace {
-// getpass.getpass(prompt): prompt on the tty, no echo, newline after
+// getpass.getpass(prompt): prompt on the tty, no echo, newline after.
+// Both go through the one shared fd-0 reader: a second buffered reader here
+// would steal the REPL's typeahead and poison EOF state.
 std::optional<std::string> GetPass(const std::string& prompt) {
-  int fd = ::open("/dev/tty", O_RDWR | O_NOCTTY);
-  bool own = fd >= 0;
-  if (fd < 0) fd = 0;
-  struct termios old, quiet;
-  bool changed = false;
-  if (::tcgetattr(fd, &old) == 0) {
-    quiet = old;
-    quiet.c_lflag &= ~(tcflag_t)ECHO;
-    changed = ::tcsetattr(fd, TCSAFLUSH, &quiet) == 0;
-  }
-  int out = own ? fd : 2;
-  (void)!::write(out, prompt.data(), prompt.size());
   std::string line;
-  bool got = false, eof = false;
-  char c;
-  while (true) {
-    ssize_t n = ::read(fd, &c, 1);
-    if (n <= 0) { eof = true; break; }
-    got = true;
-    if (c == '\n') break;
-    line.push_back(c);
-  }
-  if (changed) ::tcsetattr(fd, TCSAFLUSH, &old);
-  (void)!::write(out, "\n", 1);
-  if (own) ::close(fd);
-  if (eof && !got) return std::nullopt;  // EOFError
+  auto got = repl::LineInput::shared().read_secret(prompt, line);
+  if (got != repl::LineInput::Status::Line) return std::nullopt;  // EOFError / KeyboardInterrupt
   return line;
 }
 std::optional<std::string> Input(const std::string& prompt) {
-  std::fputs(prompt.c_str(), stdout);
-  std::fflush(stdout);
   std::string line;
-  if (!std::getline(std::cin, line)) return std::nullopt;  // EOFError
+  auto got = repl::LineInput::shared().read(prompt, line);
+  if (got != repl::LineInput::Status::Line) return std::nullopt;  // EOFError / KeyboardInterrupt
   return line;
 }
 }  // namespace