feat: /realm in TUI, daemon instance takeover (0.9.16)

Pidfile records instance+port; login restarts the service when the seat
changes. TUI /realm status|login|stop; prompts discourage filler chatter.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/tui.c

@@ -12,6 +12,7 @@
 #include "cst_models.h"
 #include "cst_parliament.h"
 #include "cst_plugins.h"
+#include "cst_realm.h"
 #include "cst_provider_switch.h"
 #include "cst_skills.h"
 #include "cst_subagent.h"
@@ -4624,6 +4625,83 @@ static void cmd_max_steps(tui_t *t, char *arg, int *quit) {
   push_system_line(t, "(max steps per turn: %d)", cfg->max_steps);
 }
 
+static void cmd_realm(tui_t *t, char *arg, int *quit) {
+  (void)quit;
+  const char *sub = arg && arg[0] ? arg : "status";
+  if (!strcmp(sub, "status") || !strcmp(sub, "show")) {
+    char *pst = cst_parliament_status_text();
+    if (pst && pst[0]) {
+      push_system_line(t, "Realm / Parliament:");
+      char *p = pst;
+      while (*p) {
+        char *nl = strchr(p, '\n');
+        if (nl)
+          *nl = 0;
+        if (p[0])
+          push_system_line(t, "  %s", p);
+        if (!nl)
+          break;
+        p = nl + 1;
+      }
+    } else {
+      push_system_line(t, "(no realm status)");
+    }
+    free(pst);
+    return;
+  }
+  if (!strcmp(sub, "stop")) {
+    if (cst_parliament_daemon_stop() != 0)
+      push_system_line(t, "Error: could not stop parliament service");
+    else
+      push_system_line(t, "(parliament service stopped)");
+    return;
+  }
+  if (!strncmp(sub, "login", 5)) {
+    char dir[OS_PATH_MAX];
+    if (cst_realm_dir(dir, sizeof(dir)) != 0 ||
+        !cst_realm_is_password_mode(dir)) {
+      push_system_line(t, "No password Realm yet. Outside TUI run:");
+      push_system_line(t, "  cst-agent --realm-password-init");
+      return;
+    }
+    char pw[256];
+    if (secret_input_run(t, "Realm password",
+                         "Unlocks this device as chair; starts the service",
+                         pw, sizeof(pw)) != 0) {
+      push_system_line(t, "(login cancelled)");
+      return;
+    }
+    const char *iid = getenv("CST_INSTANCE_ID");
+    if (!iid || !iid[0])
+      iid = "chair-local";
+    char err[256];
+    char *hand = cst_parliament_login(pw, iid, NULL, err, sizeof(err));
+    if (!hand) {
+      memset(pw, 0, sizeof(pw));
+      push_system_line(t, "Login failed: %s", err[0] ? err : "unknown");
+      return;
+    }
+    /* Show a short summary, not the full handover blob. */
+    push_system_line(t, "(logged in as chair %s)", iid);
+    if (strstr(hand, "handover_from=") &&
+        !strstr(hand, "handover_from=\n") &&
+        !strstr(hand, "handover_from=\r"))
+      push_system_line(t, "(took chair from previous device)");
+    free(hand);
+    {
+      char serr[256];
+      if (cst_parliament_daemon_start(pw, iid, 9100, serr, sizeof(serr)) != 0)
+        push_system_line(t, "warning: service: %s",
+                         serr[0] ? serr : "start failed");
+      else if (cst_parliament_daemon_running())
+        push_system_line(t, "(parliament service running)");
+    }
+    memset(pw, 0, sizeof(pw));
+    return;
+  }
+  push_system_line(t, "Usage: /realm [status|login|stop]");
+}
+
 static void cmd_status(tui_t *t, char *arg, int *quit) {
   (void)arg;
   (void)quit;
@@ -5605,6 +5683,8 @@ static const slash_cmd_t SLASH[] = {
      cmd_mouse},
     {"max-steps", "", "[N]", "tool steps allowed per turn", 1, cmd_max_steps},
     {"status", "", "", "session, model, context and settings", 1, cmd_status},
+    {"realm", "parliament login", "[status|login|stop]",
+     "Realm / parliament chair status, login, or stop service", 1, cmd_realm},
     {"cost", "usage", "", "tokens, cache hit rate and estimated cost", 1,
      cmd_cost},
     {"todo", "tasks", "", "show the agent's task list", 1, cmd_todo},