Add simple MCP server

Proof of concept of working MCP server for Probo. Currently the official
MCP library does not support session that why the server is configured
in stateless mode. It seams the input jsonschema is not used to perform
any validation, so we should figuring out how to validate the input
properly.

Signed-off-by: Bryan Frimin <bryan@getprobo.com>

go.mod

@@ -16,8 +16,10 @@ require (
 	github.com/crewjam/saml v0.5.1
 	github.com/go-chi/chi/v5 v5.2.2
 	github.com/go-chi/cors v1.2.2
+	github.com/google/jsonschema-go v0.2.1-0.20250825175020-748c325cec76
 	github.com/jackc/pgx/v5 v5.7.5
 	github.com/jhillyerd/enmime v1.3.0
+	github.com/modelcontextprotocol/go-sdk v0.4.0
 	github.com/openai/openai-go v1.8.2
 	github.com/pdfcpu/pdfcpu v0.11.0
 	github.com/prometheus/client_golang v1.22.0
@@ -99,6 +101,7 @@ require (
 	github.com/xrash/smetrics v0.0.0-20240521201337-686a1a2994c1 // indirect
 	github.com/xuri/efp v0.0.1 // indirect
 	github.com/xuri/nfp v0.0.1 // indirect
+	github.com/yosida95/uritemplate/v3 v3.0.2 // indirect
 	go.gearno.de/x/panicf v0.1.1 // indirect
 	go.opentelemetry.io/auto/sdk v1.1.0 // indirect
 	go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.37.0 // indirect