Bump github.com/anthropics/anthropic-sdk-go from 1.17.0 to 1.18.0 (#330)

Bumps [github.com/anthropics/anthropic-sdk-go](https://github.com/anthropics/anthropic-sdk-go) from 1.17.0 to 1.18.0.
- [Release notes](https://github.com/anthropics/anthropic-sdk-go/releases)
- [Changelog](https://github.com/anthropics/anthropic-sdk-go/blob/main/CHANGELOG.md)
- [Commits](https://github.com/anthropics/anthropic-sdk-go/compare/v1.17.0...v1.18.0)

---
updated-dependencies:
- dependency-name: github.com/anthropics/anthropic-sdk-go
  dependency-version: 1.18.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

go.mod

@@ -5,7 +5,7 @@ go 1.24.0
 toolchain go1.24.2
 
 require (
-	github.com/anthropics/anthropic-sdk-go v1.17.0
+	github.com/anthropics/anthropic-sdk-go v1.18.0
 	github.com/fatih/color v1.18.0
 	github.com/fsnotify/fsnotify v1.9.0
 	github.com/google/go-cmp v0.7.0

go.sum

@@ -1,5 +1,5 @@
-github.com/anthropics/anthropic-sdk-go v1.17.0 h1:BwK8ApcmaAUkvZTiQE0yi3R9XneEFskDIjLTmOAFZxQ=
-github.com/anthropics/anthropic-sdk-go v1.17.0/go.mod h1:WTz31rIUHUHqai2UslPpw5CwXrQP3geYBioRV4WOLvE=
+github.com/anthropics/anthropic-sdk-go v1.18.0 h1:jfxRA7AqZoCm83nHO/OVQp8xuwjUKtBziEdMbfmofHU=
+github.com/anthropics/anthropic-sdk-go v1.18.0/go.mod h1:WTz31rIUHUHqai2UslPpw5CwXrQP3geYBioRV4WOLvE=
 github.com/cpuguy83/go-md2man/v2 v2.0.6/go.mod h1:oOW0eioCTA6cOiMLiUPZOpcVxMig6NIQQ7OS05n1F4g=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=