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/agent_loop.c

@@ -292,7 +292,8 @@ static const char DEF_INTRO[] =
     "- Verify (build, tests, or running it) before saying it works; if you "
     "could not verify, say so.\n"
     "- Keep going until the task is done or truly blocked. Prefer acting with "
-    "tools over describing the next step; do not stop at a plan unless asked.\n\n";
+    "tools over describing the next step; do not stop at a plan unless asked. "
+    "Skip filler like \"I'll start by looking\" — call a tool immediately.\n\n";
 
 /* Same role, framed for /mode general: the workspace may hold documents,
  * data or anything else, not just code. */
@@ -312,7 +313,8 @@ static const char DEF_INTRO_GENERAL[] =
     "- Check your work when you can (re-read it, run it, cross-check the "
     "source); if you could not verify something, say so.\n"
     "- Keep going until the task is done or truly blocked. Prefer acting with "
-    "tools over describing the next step; do not stop at a plan unless asked.\n\n";
+    "tools over describing the next step; do not stop at a plan unless asked. "
+    "Skip filler like \"I'll start by looking\" — call a tool immediately.\n\n";
 
 static void put_tool_use(cst_buf_t *b, const cst_agent_config_t *cfg) {
   cst_buf_puts(b, "\nTool use:\n");