docs(embed): document control center commands

[r266-tech]

Summary

• Document the new hindsight-embed control center added by feat(embed): local control center web app #2132.
• Add the browser wizard shortcut, control start/status/logs/stop commands, localhost token/log behavior, and HINDSIGHT_EMBED_CONTROL_PORT.
• Regenerate the Hindsight docs skill mirror.

Verification

• Source-checked hindsight-embed CLI and control_center lifecycle code on main.
• Ran ./scripts/generate-docs-skill.sh, including link validation.
• git diff --check