docs: comprehensive documentation audit — fix 9 HIGH, 20+ MEDIUM gaps (#4087)

Reference docs fixes:
- cli-commands.md: remove non-existent --provider alibaba, add hermes
  profile/completion/plugins/mcp to top-level table, add --profile/-p
  global flag, add --source chat option
- slash-commands.md: add /yolo and /commands, fix /q alias conflict
  (resolves to /queue not /quit), add missing aliases (/bg, /set-home,
  /reload_mcp, /gateway)
- toolsets-reference.md: fix hermes-api-server (not same as hermes-cli,
  omits clarify/send_message/text_to_speech)
- profile-commands.md: fix show name required not optional, --clone-from
  not --from, add --remove/--name to alias, fix alias path, fix export/
  import arg types, remove non-existent fish completion
- tools-reference.md: add EXA_API_KEY to web tools requires_env
- mcp-config-reference.md: add auth key for OAuth, tool name sanitization
- environment-variables.md: add EXA_API_KEY, update provider values
- plugins.md: remove non-existent ctx.register_command(), add
  ctx.inject_message()

Feature docs additions:
- security.md: add /yolo mode, approval modes (manual/smart/off),
  configurable timeout, expanded dangerous patterns table
- cron.md: add wrap_response config, [SILENT] suppression
- mcp.md: add dynamic tool discovery, MCP sampling support
- cli.md: add Ctrl+Z suspend, busy_input_mode, tool_preview_length
- docker.md: add skills/credential file mounting

Messaging platform docs:
- telegram.md: add webhook mode, DoH fallback IPs
- slack.md: add multi-workspace OAuth support
- discord.md: add DISCORD_IGNORE_NO_MENTION
- matrix.md: add MSC3245 native voice messages
- feishu.md: expand from 129 to 365 lines (encrypt key, verification
  token, group policy, card actions, media, rate limiting, markdown,
  troubleshooting)
- wecom.md: expand from 86 to 264 lines (per-group allowlists, media,
  AES decryption, stream replies, reconnection, troubleshooting)

Configuration docs:
- quickstart.md: add DeepSeek, Copilot, Copilot ACP providers
- configuration.md: add DeepSeek provider, Exa web backend, terminal
  env_passthrough/images, browser.command_timeout, compression params,
  discord config, security/tirith config, timezone, auxiliary models

21 files changed, ~1000 lines added

website/docs/user-guide/messaging/slack.md

@@ -237,6 +237,60 @@ Make sure the bot has been **invited to the channel** (`/invite @Hermes Agent`).
 
 ---
 
+## Multi-Workspace Support
+
+Hermes can connect to **multiple Slack workspaces** simultaneously using a single gateway instance. Each workspace is authenticated independently with its own bot user ID.
+
+### Configuration
+
+Provide multiple bot tokens as a **comma-separated list** in `SLACK_BOT_TOKEN`:
+
+```bash
+# Multiple bot tokens — one per workspace
+SLACK_BOT_TOKEN=xoxb-workspace1-token,xoxb-workspace2-token,xoxb-workspace3-token
+
+# A single app-level token is still used for Socket Mode
+SLACK_APP_TOKEN=xapp-your-app-token
+```
+
+Or in `~/.hermes/config.yaml`:
+
+```yaml
+platforms:
+  slack:
+    token: "xoxb-workspace1-token,xoxb-workspace2-token"
+```
+
+### OAuth Token File
+
+In addition to tokens in the environment or config, Hermes also loads tokens from an **OAuth token file** at:
+
+```
+~/.hermes/platforms/slack/slack_tokens.json
+```
+
+This file is a JSON object mapping team IDs to token entries:
+
+```json
+{
+  "T01ABC2DEF3": {
+    "token": "xoxb-workspace-token-here",
+    "team_name": "My Workspace"
+  }
+}
+```
+
+Tokens from this file are merged with any tokens specified via `SLACK_BOT_TOKEN`. Duplicate tokens are automatically deduplicated.
+
+### How it works
+
+- The **first token** in the list is the primary token, used for the Socket Mode connection (AsyncApp).
+- Each token is authenticated via `auth.test` on startup. The gateway maps each `team_id` to its own `WebClient` and `bot_user_id`.
+- When a message arrives, Hermes uses the correct workspace-specific client to respond.
+- The primary `bot_user_id` (from the first token) is used for backward compatibility with features that expect a single bot identity.
+
+---
+
 ## Voice Messages
 
 Hermes supports voice on Slack: