fix(config): remove version field and formatters for golangci-lint v1 compatibility

The CI uses golangci-lint v1.64.8 which doesn't support:
- version: 2 field (v2-only feature)
- formatters section (v2-only feature)

Removed version field and formatters section to make config compatible with v1.
Formatting will be checked by gofmt/goimports separately if needed.

.golangci.yml

@@ -1,8 +1,6 @@
 # golangci-lint configuration
 # See https://golangci-lint.run/usage/configuration/
 
-version: 2
-
 run:
   timeout: 5m
   tests: true
@@ -18,11 +16,6 @@ linters:
   disable:
     - gocritic  # Can be enabled later for stricter checks
 
-formatters:
-  enable:
-    - gofmt
-    - goimports
-
 linters-settings:
   revive:
     rules: