feat: 新增 core/agents 模块和 nanobot

- 新增 agents 模块，包含 agent、api、skills 等子模块
- 新增 nanobot 项目，支持多渠道集成
- 添加启动脚本 start-all.bat 和 start-all.sh

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

core/nanobot/core_agent_lines.sh

@@ -0,0 +1,21 @@
+#!/bin/bash
+# Count core agent lines (excluding channels/, cli/, providers/ adapters)
+cd "$(dirname "$0")" || exit 1
+
+echo "nanobot core agent line count"
+echo "================================"
+echo ""
+
+for dir in agent agent/tools bus config cron heartbeat session utils; do
+  count=$(find "nanobot/$dir" -maxdepth 1 -name "*.py" -exec cat {} + | wc -l)
+  printf "  %-16s %5s lines\n" "$dir/" "$count"
+done
+
+root=$(cat nanobot/__init__.py nanobot/__main__.py | wc -l)
+printf "  %-16s %5s lines\n" "(root)" "$root"
+
+echo ""
+total=$(find nanobot -name "*.py" ! -path "*/channels/*" ! -path "*/cli/*" ! -path "*/providers/*" ! -path "*/skills/*" | xargs cat | wc -l)
+echo "  Core total:     $total lines"
+echo ""
+echo "  (excludes: channels/, cli/, providers/, skills/)"