Auto-generate service/resource path constants to prevent error string inconsistencies

[yimsk]

Problem

PR #71 renamed directories to kebab-case, but ~36 error strings in DAO files were missed and still use old names:

// Current (inconsistent)
apperrors.Wrap(err, "new sagemaker/trainingjobs dao")

// Expected
apperrors.Wrap(err, "new sagemaker/training-jobs dao")

This only affects debug output, not functionality, but causes confusion when debugging.

Proposal

Extend gen-imports to generate a constant in each resource package:

// Auto-generated in each register.go or new constants.go
const ServiceResource = "sagemaker/training-jobs"

Then use in DAO files:

apperrors.Wrap(err, "new "+ServiceResource+" dao")

Benefits

• Error strings always match directory structure
• No manual maintenance
• Prevents future inconsistencies

Alternatives Considered

1. Custom lint rule - Detects but doesn't fix
2. Runtime package path - Adds complexity, reflection overhead

Tasks

• Extend gen-imports to generate ServiceResource constant per package
• Update DAO files to use the constant
• Fix existing ~36 inconsistent error strings

[yimsk]

Completed in PR #83