Project refactoring changed xtlite to xtc everywhere.

docs/BUILD.md

@@ -1,6 +1,6 @@
 # Build baseline
 
-Phase 0 retains the existing layout: public C headers in `include/xtlite`,
+Phase 0 retains the existing layout: public C headers in `include/xtc`,
 C implementation modules under `src`, optional C++ GUI under `src/gui`, and
 tests under `tests`. `src/main.c` is a minimal headless startup/shutdown check;
 it does not initialize audio devices or open a GUI.
@@ -9,7 +9,7 @@ it does not initialize audio devices or open a GUI.
 
 ```sh
 make clean all test
-./build/xtlite-check
+./build/xtc-check
 make debug
 make gui
 ```

docs/IDEA.md

@@ -132,7 +132,7 @@ The C core and audio engine may be separate libraries or clearly separated modul
 Adapt this to an existing repository instead of replacing it blindly.
 
 ```text
-xtlite/
+xtc/
 ├── README.md
 ├── LICENSE
 ├── Makefile
@@ -147,12 +147,12 @@ xtlite/
 │       ├── 0002-c-core-fltk-gui.md
 │       └── 0003-realtime-thread-rules.md
 ├── include/
-│   └── xtlite/
-│       ├── xtlite.h
-│       ├── xtlite_types.h
-│       ├── xtlite_project.h
-│       ├── xtlite_engine.h
-│       └── xtlite_version.h
+│   └── xtc/
+│       ├── xtc.h
+│       ├── xtc_types.h
+│       ├── xtc_project.h
+│       ├── xtc_engine.h
+│       └── xtc_version.h
 ├── src/
 │   ├── core/
 │   ├── project/
@@ -222,8 +222,8 @@ Keep C and C++ files clearly separated. C headers exposed to C++ must use `exter
 Example API shape (illustrative only; refine after reviewing the actual codebase):
 
 ```c
-#ifndef XTLITE_H
-#define XTLITE_H
+#ifndef XTC_H
+#define XTC_H
 
 #ifdef __cplusplus
 extern "C" {