build(cmake): add pofiles dep to every NLS-aware executable - #98

Followup to #94 — found while exercising partial-target builds during VM testing of the manpage pipeline.

Summary

gettext_process_po_files puts the per-language .gmo build in CMake's all target but adds no dependency to any specific binary target. So building one binary in isolation — e.g. cmake --build build --target amuled — silently skips the .gmo step entirely on Linux. The subsequent cmake --install build then errors with:

CMake Error at build/po/cmake_install.cmake:46 (file):
  file INSTALL cannot find ".../build/po/ar.gmo": No such file or directory.

because the install (FILES ${gmo}) rules issued from po/CMakeLists.txt fire unconditionally for every enabled language. Reproduces against any partial-target build on Linux.

Add a single sweeping add_dependencies(..., pofiles) loop at the end of src/CMakeLists.txt covering every executable aMule ships:

amule amuled amulecmd amulegui amuleweb ed2k alc alcc cas wxcas fileview

pofiles is the aggregator target that gettext_process_po_files maintains internally — making each binary depend on it pulls the full catalog build into any partial-target invocation. Gated on ENABLE_NLS AND TARGET pofiles, which also covers the ENABLE_NLS=YES-but-msgfmt-missing edge case where po/ isn't entered.

Test plan

Run on Ubuntu 26.04 ARM64.

• Before fix (master tip) — cmake -B build -DBUILD_DAEMON=YES && cmake --build build --target amuled && cmake --install build → CMake Error … file INSTALL cannot find .../build/po/ar.gmo
• After fix — same sequence: 37 .gmo files built as a side effect of --target amuled, install completes cleanly, 37 .mo files land at share/locale/<lang>/LC_MESSAGES/amule.mo
• --target for any other binary (verified amulecmd, ed2k) pulls in the same 37-file catalog build
• ENABLE_NLS=OFF configure still works — the loop is a no-op since TARGET pofiles is false
• macOS configure still works — the dependency lands the same way; the .mo install path is Mac-specific (POST_BUILD on the .app bundle, no install(FILES ${gmo}) rule), so this fix is invisible there but not harmful
• Full cmake --build build (ALL) behavior unchanged — .gmo was already in all, this just adds a redundant edge

Scope

Only the catalog dependency. The orthogonal issue of cmake --install build failing on binaries you didn't build (e.g. --target amuled then trying to install amulecmd) is separate scope; it requires either making install depend on its target arguments or accepting the current "build everything, then install" contract. Not addressed here.