Add Swagger UI API page to /docs

[Bjorkan]

Summary

• Add a custom /docs Swagger UI page for the RemoteTerm API
• Improve OpenAPI metadata with richer API description, tag descriptions, and common error response docs
• Add an “API Docs” button beside “Add Integration” in the MQTT & Automation settings section
• Proxy /docs and /openapi.json through Vite dev server so the docs work from localhost:5173

Testing

• ./scripts/quality/all_quality.sh Passed

Screenshots

[jkingsman]

Love the API and formatting improvements. Thanks! I don't think that having the API docs linked from the integrations area makes a lot of sense, since there's basically nothing in that area where having API knowledge is terribly relevant, but I'm open to making it more clear in availability in either (both?) of the readmes.

[Bjorkan]

Love the API and formatting improvements. Thanks! I don't think that having the API docs linked from the integrations area makes a lot of sense, since there's basically nothing in that area where having API knowledge is terribly relevant, but I'm open to making it more clear in availability in either (both?) of the readmes.

Of course! I just whipped something together! It was kinda helpful to me atleast to see the API avaliable 😆

[jkingsman]

If you remove the link I'd happily merge as is 🙂

[Bjorkan]

If you remove the link I'd happily merge as is 🙂

Will check that tomorrow!

[jkingsman]

Thanks for the PR! ♥