v1.2.3: Two bots on one machine keep their own state

Added

• Every per-instance path derives from one setting. BOT_ID (default
  cc-telegram-bot) governs ~/<.BOT_ID>/ (sessions, audit log, alert database),
  /tmp/<BOT_ID>/ (downloaded media) and /run/<BOT_ID>/alerts.sock. Validated as a single
  path segment at startup, so a value like ../../etc aborts instead of escaping into the
  filesystem
• The bot's role description can be changed without editing the source. BOT_PERSONA
  (default unchanged) sets the one-line role description at the top of the system prompt; the
  detailed personality stays in CLAUDE.md inside CLAUDE_WORKING_DIR

Fixed

• Two instances of this bot on one machine shared their state without saying so. The data
  directory (~/.cc-telegram-bot) and temp directory (/tmp/telegram-bot) were hardcoded, so
  both wrote the same sessions.json: last write won, and a conversation could surface in the
  wrong bot. Set a distinct BOT_ID per instance
• A bot without alerting no longer carries the alert half of the safety prompt. The alert
  rules (7 through 12, roughly half the safety prompt) were emitted unconditionally. They now
  follow the same gate as the runtime, since the alert socket only starts when a group is
  whitelisted (src/index.ts), so the rules only appear when TELEGRAM_ALLOWED_GROUPS is
  set. Without alerts the prompt drops from 4097 to 2181 characters, and the bot no longer
  carries instructions to scan DOCS_DIR and await /alert approval for a subsystem that
  never runs
• A bot built on this code for another purpose was told it was an admin bot. The persona
  line was hardcoded as "You are a Claude-powered Telegram admin bot", which outranked the
  bot's own CLAUDE.md, because the system prompt wins

Changed

• Dependencies raised: Claude Agent SDK 0.3.215 -> 0.3.233, MCP SDK 1.29.0 -> 1.30.0,
  TypeScript ^5 -> ^5.9.3