Use standard API abstractions

Prefer established, type-safe abstractions over primitive types or direct property access when designing APIs. This improves maintainability, enables future extensibility, and provides better developer experience.

Use standard library types and framework-provided abstractions instead of custom primitives:

• Use google.protobuf.Duration instead of int64 millisecond fields
• Use std::string_view instead of const char* for string parameters
• Use framework argument builders instead of direct property access like .path

Example improvements:

// Instead of:
static bool IsValidEnvName(const char* p) { ... }

// Use:
static bool IsValidEnvName(std::string_view name) { ... }

// Instead of:
int64 critical_path_time_in_ms = 4;

// Use:
google.protobuf.Duration critical_path_time = 4;

These abstractions often provide additional functionality (like automatic path mapping, timezone handling, or memory efficiency) and make APIs more robust and future-proof.