docs: add Phase 3 chat architecture and overview documentation

- Add docs/kugetsu-chat.md:
  - Model B architecture (separate Chat/PM agents)
  - Session types (chat-agent, pm-agent, pm-agent-{repo}, issue sessions)
  - Hybrid message routing
  - PM Agent modes (notify/silent)
  - Context management (local + Gitea fetch on-demand)
  - Example flows

- Add docs/kugetsu.md:
  - Overview of kugetsu system
  - Quick start guide
  - Links to all documentation

- Update docs/kugetsu-architecture.md:
  - Add Phase 3 architecture section
  - Update success criteria
  - Add Phase 3 design decisions

- Add docs/telegram-setup.md:
  - BotFather bot creation guide
  - Security notes

- Remove ssh-keygen.sh (not needed)

docs/telegram-setup.md

@@ -0,0 +1,96 @@
+# Telegram Bot Setup Guide
+
+This guide covers creating and configuring a Telegram bot for kugetsu Phase 3 (Chat Integration).
+
+## Create a Telegram Bot
+
+### Step 1: Start BotFather
+
+1. Open Telegram and search for **@BotFather**
+2. Click **Start** to begin
+
+### Step 2: Create New Bot
+
+Send the command:
+```
+/newbot
+```
+
+BotFather will ask for:
+1. **Name** - A human-readable name (e.g., "Kugetsu Bot")
+2. **Username** - Must end in `bot` (e.g., `kugetsu_agent_bot`)
+
+### Step 3: Save Your Token
+
+BotFather will give you a token like:
+```
+1234567890:ABCdefGHIjklMNOpqrSTUvwxyz123456789
+```
+
+**⚠️ Keep this token secret!** It allows access to your bot.
+
+### Step 4: Set Bot Description (Optional)
+
+```
+/setdescription
+```
+Enter a description like: "Kugetsu Chat Agent - Interact with your agent via Telegram"
+
+### Step 5: Set Bot Picture (Optional)
+
+```
+/setuserpic
+```
+Upload a profile picture for the bot.
+
+---
+
+## Configure Hermes for Telegram
+
+*(This section will be expanded when Phase 3 implementation begins)*
+
+### Required Environment Variables
+
+```bash
+TELEGRAM_BOT_TOKEN="your-bot-token-here"
+TELEGRAM_API_ID="your-api-id"  # From https://my.telegram.org
+TELEGRAM_API_HASH="your-api-hash"  # From https://my.telegram.org
+```
+
+### Hermes Configuration
+
+```yaml
+# hermes/config.yaml
+telegram:
+  enabled: true
+  bot_token: ${TELEGRAM_BOT_TOKEN}
+```
+
+---
+
+## Security Notes
+
+- **Never commit bot tokens** to version control
+- Use environment variables or secrets management
+- Rotate tokens if compromised: `/revoke` in BotFather
+
+---
+
+## Troubleshooting
+
+### Bot Not Responding
+
+1. Check bot token is correct
+2. Verify Hermes is running and connected
+3. Check bot has not been blocked by user
+
+### "Bot was blocked by the user"
+
+The user has blocked your bot. They need to unblock it or start a new chat.
+
+---
+
+## See Also
+
+- [Phase 3: Chat Integration (Issue #19)](../issues/19)
+- [kugetsu Chat Architecture](kugetsu-chat.md)