Add Scala language support

[jschatz1]

Description

Add Scala parsing support for JVM teams using Scala with Spark, Akka, and Play Framework.

What to Implement

1. Add `go-tree-sitter/scala` dependency
2. Add Scala parser initialization in `kai-core/parse/parse.go`
3. Implement symbol extraction — classes, objects, traits, case classes, methods, vals
4. Implement call/import extraction — `import` statements, method calls
5. Add `.scala` and `.sc` extension detection
6. Add tests

Files to Modify

• `kai-core/parse/parse.go`
• `kai-core/parse/calls.go`
• `kai-core/detect/detect.go`
• `kai-core/go.mod`