Meson + Ninja build support (371s vs 447s cold build)

[0xkhalz]

I tested building codebase-memory-mcp with Meson + Ninja on my laptop (i5-8250U 4C/8T, 8GB RAM, Arch Linux, GCC 16.2.1) and compared it against Makefile.cbm.

Make (make -j8 -f Makefile.cbm cbm)

Built: build/c/codebase-memory-mcp
=== Build complete: build/c/codebase-memory-mcp ===

________________________________________________________
Executed in  447.33 secs    fish           external
   usr time   18.16 mins   51.00 micros   18.16 mins
   sys time    0.29 mins  649.00 micros    0.29 mins

Meson + Ninja (ninja -C build-release codebase-memory-mcp)

[430/430] Linking target codebase-memory-mcp

________________________________________________________
Executed in  371.65 secs    fish           external
   usr time   28.56 mins    0.00 millis   28.56 mins
   sys time    0.45 mins    4.50 millis    0.45 mins

Meson + Ninja finished ~76s faster (371.65s vs 447.33s, even with -O3 vs -O2) because Makefile.cbm (line 1394) compiles all PROD_SRCS and EXTRACTION_SRCS in a single $(CC) call at the end rather than compiling .o files in parallel. Incremental rebuilds after editing a single file in src/ also take ~1-2s instead of recompiling all first-party sources.

Branch with the Meson build files (meson.build, src/meson.build, vendored/meson.build, tests/meson.build):
https://github.com/0xkhalz/codebase-memory-mcp/tree/feat/meson-build-system

Would you be interested in a PR adding Meson support (or alternatively splitting PROD_SRCS into .o targets in Makefile.cbm)?