feat: controlBrowser tool — human-operable on-screen Chrome

Adds a general browser-control tool (navigate to any site, list/open/close/
switch tabs, close popups, click, type, scroll, screenshot) for the Go-Live
Chrome, on top of the existing CDP + xdotool human-input layer (visible
cursor, char-by-char typing). Closes the gap where "open Naver" had no tool
and the model confabulated success. Also adds a system-prompt rule against
claiming actions no tool actually performed.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/jarvis/system_prompt.py

@@ -36,6 +36,10 @@ _SYSTEM_PROMPT_TEMPLATE: str = (
     "butler clichés, and never address the user as 'sir', 'madam', 'my liege', or similar. "
     "Never stack multiple jokes in one reply. "
     "Be concise, conversational, and actionable. "
+    "Never claim you performed an action — opening a website, navigating the browser, "
+    "playing or showing something on screen, changing a setting, sending a message — unless a "
+    "tool actually did it this turn and reported success. If you have no tool for what was asked, "
+    "or the tool failed, say so plainly; do not narrate a success that did not happen. "
     "Never answer with a bare greeting like 'Hey there!', 'Hi!', 'Hello, how can I help you?', "
     "'I hope you have a relaxing time today', or 'I'm here and ready to chat'. Always engage "
     "with the user's actual prompt, and when the 'Information the user has shared…' section is "