What

Update Doxyfile INPUT paths so generated documentation reflects the new include/kcenon/container/ + src/ layout. Update install(DIRECTORY ...) rules so only include/kcenon/container/ is exported (not the legacy include/container/).

Why

After the header consolidation and source migration, Doxyfile still references the old feature-directory paths and would generate empty/incorrect docs. The install rules likewise still walk the old roots, which would either install nothing or install the legacy forwarding tree alongside the canonical one.

Where

• Doxyfile (INPUT, EXAMPLE_PATH, IMAGE_PATH if any)
• cmake/install.cmake (or wherever install(DIRECTORY ...) lives after the CMake decomposition sub-issue lands)

How

Technical Approach

1. Repoint Doxyfile INPUT to include/kcenon/container/ src/.
2. Drop legacy paths (core/ internal/ integration/ messaging/ include/container/) from INPUT and any other path-list keys.
3. Update install(DIRECTORY include/kcenon/container/ DESTINATION include/kcenon/container) and remove the legacy directory install rule.
4. Generate docs locally (doxygen Doxyfile) and inspect output for "no input files" or empty modules.
5. Verify cmake --install build/ --prefix /tmp/inst produces only the canonical layout.

Dependencies

• Should land last so the new paths are stable.

Acceptance Criteria

• doxygen Doxyfile runs without "no input files" / "input directory not found" warnings
• Generated HTML covers all current public types
• cmake --install produces only include/kcenon/container/ (no include/container/ unless intentionally kept during the deprecation window)
• Install manifest size is comparable to pre-split baseline (≤ small delta)

Estimated Size

S. Mostly path edits + a verification pass.

Part of #531