Fix docs for current Hermes gateway, sandbox, and MCP flows

[Shoutoutdigitalau]

Summary

• replace invalid quickstart/systemd hermes run usage with current hermes gateway ... commands
• rewrite remote sandbox guidance away from nonexistent hermes sandbox, /sandbox, and top-level sandboxes: toward terminal.backend, worktrees, Kanban, and external CLI/MCP/skill integrations
• move MCP setup docs/templates/wizard/audit skill to hermes mcp add/list/test/configure, while noting Hermes may persist MCP entries internally

Verification

• focused stale scans found no command-level hermes run, hermes sandbox, /sandbox, --listen, /usr/local/bin/hermes, top-level sandboxes:, or top-level mcp_servers: examples
• Hermes CLI help checks passed for gateway, dashboard, and mcp add/list/test/configure
• YAML parse over all .yml / .yaml files passed
• python .github/scripts/validate_skills.py passed all 13 skills
• wizard inline JavaScript parses with Node
• focused Prettier check passed on touched Markdown/SKILL files
• git diff --check exits 0

Notes

• bash -n scripts/vps-bootstrap.sh was not runnable on the Windows host because local WSL cannot attach its VHDX path.
• repo-wide yamllint still fails on pre-existing Windows CRLF line-ending noise; YAML syntax parsing passes.

[Shoutoutdigitalau]

Closing this PR because this branch was created during an internal validation pass and is not intended for upstream contribution.