Bump github.com/anthropics/anthropic-sdk-go from 1.14.0 to 1.16.0

Bumps [github.com/anthropics/anthropic-sdk-go](https://github.com/anthropics/anthropic-sdk-go) from 1.14.0 to 1.16.0.
- [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/v1.14.0...v1.16.0)

---
updated-dependencies:
- dependency-name: github.com/anthropics/anthropic-sdk-go
  dependency-version: 1.16.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

go.mod

@@ -5,7 +5,7 @@ go 1.24.0
 toolchain go1.24.2
 
 require (
-	github.com/anthropics/anthropic-sdk-go v1.14.0
+	github.com/anthropics/anthropic-sdk-go v1.16.0
 	github.com/fatih/color v1.18.0
 	github.com/fsnotify/fsnotify v1.9.0
 	github.com/ncruces/go-sqlite3 v0.29.1