docs(readme): use the 1600px hero GIF at 800px display width

The 800px GIF rendered the header stats strip (CPU, MEM, 5H/7D) at ~5px
text height. The 1600px source shown at width=800 stays sharp on high-DPI
screens. New filename so GitHub's image cache serves the new file.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

README.md

@@ -24,7 +24,7 @@
 </p>
 
 <p align="center">
-  <img src="docs/images/tiles-crt-stats-20261010.gif" alt="Codeman tile grid: six live agents (DeepSeek Harness, Claude Code, Pi, Codex, OpenCode and a shell) powering on and off with the CRT animation, with the live header strip showing CPU, memory and Claude plan usage" width="800">
+  <img src="docs/images/tiles-crt-stats-1600-20261010.gif" alt="Codeman tile grid: six live agents (DeepSeek Harness, Claude Code, Pi, Codex, OpenCode and a shell) powering on and off with the CRT animation, with the live header strip showing CPU, memory and Claude plan usage" width="800">
 </p>
 
 **Codeman** is a self-hosted mission control for AI coding agents. It spawns Claude Code, OpenCode, Codex, Antigravity, Gemini, Pi, Grok, DeepSeek Harness, or OMP inside persistent tmux sessions, streams the real terminal to any browser, and keeps agents productive after you walk away: it re-prompts on idle, resumes when a usage limit resets, runs scheduled jobs, and shows every background agent working in real time.

README.zh-CN.md

@@ -24,7 +24,7 @@
 </p>
 
 <p align="center">
-  <img src="docs/images/tiles-crt-stats-20261010.gif" alt="Codeman 平铺视图：六个实时智能体（DeepSeek Harness、Claude Code、Pi、Codex、OpenCode 和一个 shell）以 CRT 动画开启与关闭，顶部实时显示 CPU、内存和 Claude 套餐用量" width="800">
+  <img src="docs/images/tiles-crt-stats-1600-20261010.gif" alt="Codeman 平铺视图：六个实时智能体（DeepSeek Harness、Claude Code、Pi、Codex、OpenCode 和一个 shell）以 CRT 动画开启与关闭，顶部实时显示 CPU、内存和 Claude 套餐用量" width="800">
 </p>
 
 > 本文档由英文版 [`README.md`](README.md) 翻译而来。如有出入，以英文版为准。