fix: add dir field to goreleaser build config

- Add explicit dir: . to build configuration
- Add trailing slash to main path for clarity
- Should fix "couldn't find main file" error

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: jackspirou

.goreleaser.yaml

@@ -7,8 +7,9 @@ before:
 
 builds:
   - id: tokenizer
-    main: ./cmd/tokenizer
+    main: ./cmd/tokenizer/
     binary: tokenizer
+    dir: .
     env:
       - CGO_ENABLED=0
     goos: