What

Move all .cpp source files from feature directories into src/{core,internal,integration,messaging}/, leaving the root-level feature directories empty so they can be removed.

Current scattered sources:

• core/ — 9 sources
• internal/ — 3 sources
• integration/ — 1 source
• messaging/ — 1 source

Target: src/{core,internal,integration,messaging}/.

Why

After the header consolidation (depends on #), feature directories still hold ~14 .cpp files. Sources mixed with headers in feature directories block clean install(DIRECTORY ...) rules and prevent removal of the four root-level directories. Centralising sources in src/ matches the canonical template used by sibling repos in the EPIC.

Where

• Source: core/, internal/, integration/, messaging/ (.cpp only)
• Target: src/{core,internal,integration,messaging}/
• Affected: target source lists in CMakeLists.txt

How

Technical Approach

1. Wait for header consolidation (#) to merge so #include paths are stable.
2. Move .cpp files preserving subdirectory structure.
3. Update every target_sources(... PRIVATE ...) entry in CMakeLists.txt and any cmake module that lists sources by absolute or repo-relative path.
4. Verify core/, internal/, integration/, messaging/ are now empty and remove them.
5. Run full build + tests.

Dependencies

• Blocked by: header consolidation sub-issue (must merge first to keep #include resolution stable while sources move)

Acceptance Criteria

• Feature directories at repo root removed (core/, internal/, integration/, messaging/ no longer exist)
• All sources under src/
• CMake targets compile against the new source paths
• Full build green, ctest passes
• Downstream consumers still build

Estimated Size

M (~14 cpp moves + CMake source list updates).

Part of #531