feat: add idempotent global CLAUDE.md install with start/end markers

Uses <!-- server-manager:start/end --> markers to safely add or replace
the server-manager section. Re-running install_all() updates the block
without creating duplicates.

Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>

core/claude_setup.py

@@ -24,6 +24,25 @@ SKILL_SRC = os.path.join(_BASE_DIR, "tools", "skill-ssh.md")
 SKILL_DST_DIR = os.path.expanduser("~/.claude/commands")
 SKILL_DST = os.path.join(SKILL_DST_DIR, "ssh.md")
 SSH_KEY_PATH = os.path.expanduser("~/.ssh/id_ed25519")
+GLOBAL_CLAUDE_MD = os.path.expanduser("~/.claude/CLAUDE.md")
+
+_BLOCK_START = "<!-- server-manager:start -->"
+_BLOCK_END = "<!-- server-manager:end -->"
+
+GLOBAL_CLAUDE_MD_BLOCK = f"""{_BLOCK_START}
+## Server Manager — управление серверами
+
+**ВСЕГДА** используй server manager для подключения к серверам. Никогда не используй `ssh`, `sshpass` или прямые подключения.
+
+- Скилл: `/ssh ALIAS "command"` — выполнить команду на сервере
+- Список серверов: `python3 ~/.server-connections/ssh.py --list`
+- Документация: `~/.claude/commands/ssh.md`
+- Memory bank: проект `global-infrastructure` → `techContext.md`
+- Инфраструктура: https://git.sensey24.ru/aibot777/infrastructure-docs
+
+**Запрещено:** использовать `ssh`, `sshpass`, читать `~/.server-connections/` напрямую, раскрывать IP/пароли/порты.
+{_BLOCK_END}
+"""
 
 
 def check_status() -> dict:
@@ -112,6 +131,41 @@ def generate_ssh_key() -> str:
     return f"Key generated: {SSH_KEY_PATH}"
 
 
+def install_global_claude_md() -> str:
+    """Add/update server manager section in global ~/.claude/CLAUDE.md.
+
+    Uses start/end markers to safely replace existing block without duplication.
+    """
+    import re
+    os.makedirs(os.path.dirname(GLOBAL_CLAUDE_MD), exist_ok=True)
+
+    existing = ""
+    if os.path.exists(GLOBAL_CLAUDE_MD):
+        with open(GLOBAL_CLAUDE_MD, encoding="utf-8") as f:
+            existing = f.read()
+
+    pattern = re.compile(
+        re.escape(_BLOCK_START) + r".*?" + re.escape(_BLOCK_END),
+        re.DOTALL
+    )
+
+    if pattern.search(existing):
+        # Блок уже есть — заменяем на актуальную версию
+        updated = pattern.sub(GLOBAL_CLAUDE_MD_BLOCK.strip(), existing)
+        with open(GLOBAL_CLAUDE_MD, "w", encoding="utf-8") as f:
+            f.write(updated)
+        log.info(f"Global CLAUDE.md block updated: {GLOBAL_CLAUDE_MD}")
+        return f"Global CLAUDE.md block updated: {GLOBAL_CLAUDE_MD}"
+    else:
+        # Блока нет — добавляем в конец
+        with open(GLOBAL_CLAUDE_MD, "a", encoding="utf-8") as f:
+            if existing and not existing.endswith("\n"):
+                f.write("\n")
+            f.write("\n" + GLOBAL_CLAUDE_MD_BLOCK)
+        log.info(f"Global CLAUDE.md block added: {GLOBAL_CLAUDE_MD}")
+        return f"Global CLAUDE.md block added: {GLOBAL_CLAUDE_MD}"
+
+
 def install_all() -> list[str]:
     """Full setup — install everything."""
     results = []
@@ -120,6 +174,7 @@ def install_all() -> list[str]:
         ("ssh_script", install_ssh_script),
         ("skill", install_skill),
         ("ssh_key", generate_ssh_key),
+        ("global_claude_md", install_global_claude_md),
     ]
 
     for name, func in steps: