What

When LOGGER_HAS_OTLP is not defined (default), otlp_writer.cpp export_with_http() builds a complete OTLP JSON payload but returns true without sending it. No warning is logged.

• LOGGER_ENABLE_OTLP is OFF by default (CMakeLists.txt:59)
• Callers believe telemetry data is being exported when it is silently discarded

Why

Silent data loss in observability pipelines. Users who configure OTLP export get no indication their logs are not reaching the collector.

How

Technical Approach

Change the stub to return false and emit a one-time stderr warning explaining that OTLP transport is unavailable.

Acceptance Criteria

• Stub mode returns false instead of true
• One-time warning printed to stderr on first call
• Warning message includes build instructions (LOGGER_ENABLE_OTLP=ON)