chore: add jsonschema dependency for structured output validation

Add github.com/santhosh-tekuri/jsonschema v1.2.4 for JSON schema validation
support in structured tool outputs.

Author: davidleitw

go.mod

@@ -4,6 +4,7 @@ go 1.23
 
 require (
 	github.com/google/uuid v1.6.0
+	github.com/santhosh-tekuri/jsonschema v1.2.4
 	github.com/spf13/cast v1.7.1
 	github.com/stretchr/testify v1.9.0
 	github.com/yosida95/uritemplate/v3 v3.0.2

go.sum

@@ -14,6 +14,8 @@ github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZb
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/rogpeppe/go-internal v1.9.0 h1:73kH8U+JUqXU8lRuOHeVHaa/SZPifC7BkcraZVejAe8=
 github.com/rogpeppe/go-internal v1.9.0/go.mod h1:WtVeX8xhTBvf0smdhujwtBcq4Qrzq/fJaraNFVN+nFs=
+github.com/santhosh-tekuri/jsonschema v1.2.4 h1:hNhW8e7t+H1vgY+1QeEQpveR6D4+OwKPXCfD2aieJis=
+github.com/santhosh-tekuri/jsonschema v1.2.4/go.mod h1:TEAUOeZSmIxTTuHatJzrvARHiuO9LYd+cIxzgEHCQI4=
 github.com/spf13/cast v1.7.1 h1:cuNEagBQEHWN1FnbGEjCXL2szYEXqfJPbP2HNUaca9Y=
 github.com/spf13/cast v1.7.1/go.mod h1:ancEpBxwJDODSW/UG4rDrAqiKolqNNh2DX3mk86cAdo=
 github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=