api: Use Huma to generate swagger docs and parse JSON automatically (#262)

## Motivation and Context

Currently there's a lot of unsafe manual JSON unmarshalling/marshalling,
and we have to manually keep the openapi schema in sync.

This PR migrates the API to
[Huma](https://github.com/danielgtaylor/huma), which appears like a
popular, well-maintained way to build APIs in Golang. I'm not a Golang
expert, but seemed highly recommended by Reddit + Claude and has a
decent star count. It provides automatic openapi spec generation and
docs hosting, JSON parsing, as well as the ability to add auth
middlewares etc.

## How Has This Been Tested?

Running locally, and poking at the endpoints

## Breaking Changes

Docs are served at `/docs` rather than `/v0/swagger/index.html` now

## Types of changes
<!-- What types of changes does your code introduce? Put an `x` in all
the boxes that apply: -->
- [ ] Bug fix (non-breaking change which fixes an issue)
- [x] New feature (non-breaking change which adds functionality)
- [x] Breaking change (fix or feature that would cause existing
functionality to change)
- [x] Documentation update

## Checklist
<!-- Go over all the following points, and put an `x` in all the boxes
that apply. -->
- [x] I have read the [MCP
Documentation](https://modelcontextprotocol.io)
- [x] My code follows the repository's style guidelines
- [x] New and existing tests pass locally
- [x] I have added appropriate error handling
- [x] I have added or updated documentation as needed

## Additional context
<!-- Add any other context, implementation notes, or design decisions
-->

go.mod

@@ -4,30 +4,22 @@ go 1.24.0
 
 require (
 	github.com/caarlos0/env/v11 v11.3.1
+	github.com/danielgtaylor/huma/v2 v2.34.1
 	github.com/google/uuid v1.6.0
 	github.com/santhosh-tekuri/jsonschema/v5 v5.3.1
 	github.com/stretchr/testify v1.10.0
-	github.com/swaggo/files v1.0.1
-	github.com/swaggo/http-swagger v1.3.4
 	go.mongodb.org/mongo-driver v1.17.3
-	golang.org/x/net v0.42.0
 )
 
 require (
-	github.com/KyleBanks/depth v1.2.1 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
-	github.com/go-openapi/jsonpointer v0.21.1 // indirect
-	github.com/go-openapi/jsonreference v0.21.0 // indirect
-	github.com/go-openapi/spec v0.21.0 // indirect
-	github.com/go-openapi/swag v0.23.1 // indirect
 	github.com/golang/snappy v0.0.4 // indirect
-	github.com/josharian/intern v1.0.0 // indirect
-	github.com/klauspost/compress v1.16.7 // indirect
-	github.com/mailru/easyjson v0.9.0 // indirect
+	github.com/klauspost/compress v1.18.0 // indirect
+	github.com/kr/text v0.2.0 // indirect
 	github.com/montanaflynn/stats v0.7.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/rogpeppe/go-internal v1.11.0 // indirect
 	github.com/stretchr/objx v0.5.2 // indirect
-	github.com/swaggo/swag v1.16.4 // indirect
 	github.com/xdg-go/pbkdf2 v1.0.0 // indirect
 	github.com/xdg-go/scram v1.1.2 // indirect
 	github.com/xdg-go/stringprep v1.0.4 // indirect
@@ -35,6 +27,6 @@ require (
 	golang.org/x/crypto v0.41.0 // indirect
 	golang.org/x/sync v0.16.0 // indirect
 	golang.org/x/text v0.28.0 // indirect
-	golang.org/x/tools v0.35.0 // indirect
+	gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )