fix(bluebubbles): add missing integration points and documentation (#6460)

- hermes_cli/skills_config.py: add platform label for per-platform skill config
- gateway/session.py: add to PII-safe platforms (no mention system)
- website/docs/user-guide/messaging/bluebubbles.md: full setup guide
- website/sidebars.ts: sidebar navigation entry
- 10 docs pages: add BlueBubbles to all platform enumerations
  (env vars, toolsets, cron delivery, gateway internals, etc.)

website/docs/index.md

@@ -46,7 +46,7 @@ It's not a coding copilot tethered to an IDE or a chatbot wrapper around a singl
 
 - **A closed learning loop** — Agent-curated memory with periodic nudges, autonomous skill creation, skill self-improvement during use, FTS5 cross-session recall with LLM summarization, and [Honcho](https://github.com/plastic-labs/honcho) dialectic user modeling
 - **Runs anywhere, not just your laptop** — 6 terminal backends: local, Docker, SSH, Daytona, Singularity, Modal. Daytona and Modal offer serverless persistence — your environment hibernates when idle, costing nearly nothing
-- **Lives where you do** — CLI, Telegram, Discord, Slack, WhatsApp, Signal, Matrix, Mattermost, Email, SMS, DingTalk, Feishu, WeCom, Home Assistant — 14+ platforms from one gateway
+- **Lives where you do** — CLI, Telegram, Discord, Slack, WhatsApp, Signal, Matrix, Mattermost, Email, SMS, DingTalk, Feishu, WeCom, BlueBubbles, Home Assistant — 15+ platforms from one gateway
 - **Built by model trainers** — Created by [Nous Research](https://nousresearch.com), the lab behind Hermes, Nomos, and Psyche. Works with [Nous Portal](https://portal.nousresearch.com), [OpenRouter](https://openrouter.ai), OpenAI, or any endpoint
 - **Scheduled automations** — Built-in cron with delivery to any platform
 - **Delegates & parallelizes** — Spawn isolated subagents for parallel workstreams. Programmatic Tool Calling via `execute_code` collapses multi-step pipelines into single inference calls