docs: fix all remaining minor accuracy issues

- updating.md: Note that 'hermes update' auto-handles config migration
- cli.md: Add summary_model to compression config, fix display config
  (add personality/compact), remove unverified pastes/ claim
- configuration.md: Add 5 missing config sections (stt, human_delay,
  code_execution, delegation, clarify), fix display defaults,
  fix reasoning_effort default to empty/unset
- messaging/index.md: Add GATEWAY_ALLOWED_USERS to security section
- skills.md: Add category field to skills_list return value
- mcp.md: Document auto-registered utility tools (resources/prompts)
- architecture.md: Fix file_tools.py reference, base_url default to None,
  synchronous agent loop pseudocode
- cli-commands.md: Fix hermes logout description
- environment-variables.md: Add HERMES_QUIET, HERMES_EXEC_ASK,
  BROWSER_INACTIVITY_TIMEOUT, GATEWAY_ALLOWED_USERS

Verification scan: 27/27 checks passed, zero issues remaining.

website/docs/user-guide/features/mcp.md

@@ -159,6 +159,10 @@ mcp_{server_name}_{tool_name}
 
 Tools appear alongside built-in tools — the agent calls them like any other tool.
 
+:::info
+In addition to the server's own tools, each MCP server also gets 4 utility tools auto-registered: `list_resources`, `read_resource`, `list_prompts`, and `get_prompt`. These allow the agent to discover and use MCP resources and prompts exposed by the server.
+:::
+
 ### Reconnection
 
 If an MCP server disconnects, Hermes automatically reconnects with exponential backoff (1s, 2s, 4s, 8s, 16s — max 5 attempts). Initial connection failures are reported immediately.