fix(zephyr): match CMake source references to lowercase filenames

Linux CI is case-sensitive; repository files are arbiter_*.c while CMake still
referenced legacy ARBITER_*.c names. Update root and subsystem CMake files.

Co-Authored-By: Oz <oz-agent@warp.dev>

Author: tbitcs

CMakeLists.txt

@@ -3,18 +3,18 @@
 if(CONFIG_ARBITER)
   zephyr_library()
   zephyr_library_sources(
-    ${CMAKE_CURRENT_LIST_DIR}/lib/ARBITER_engine.c
-    ${CMAKE_CURRENT_LIST_DIR}/lib/ARBITER_fact_store.c
-    ${CMAKE_CURRENT_LIST_DIR}/lib/ARBITER_eval.c
-    ${CMAKE_CURRENT_LIST_DIR}/lib/ARBITER_trace.c
+    ${CMAKE_CURRENT_LIST_DIR}/lib/arbiter_engine.c
+    ${CMAKE_CURRENT_LIST_DIR}/lib/arbiter_fact_store.c
+    ${CMAKE_CURRENT_LIST_DIR}/lib/arbiter_eval.c
+    ${CMAKE_CURRENT_LIST_DIR}/lib/arbiter_trace.c
   )
 
   zephyr_library_sources_ifdef(CONFIG_ARBITER_BLOB_LOADER
-    ${CMAKE_CURRENT_LIST_DIR}/lib/ARBITER_blob.c
+    ${CMAKE_CURRENT_LIST_DIR}/lib/arbiter_blob.c
   )
 
   zephyr_library_sources_ifdef(CONFIG_ARBITER_ACTION_DISPATCHER
-    ${CMAKE_CURRENT_LIST_DIR}/lib/ARBITER_action.c
+    ${CMAKE_CURRENT_LIST_DIR}/lib/arbiter_action.c
   )
 
   zephyr_include_directories(${CMAKE_CURRENT_LIST_DIR}/include)

LEDGER.md

@@ -1,5 +1,15 @@
 # Change Ledger
 
+## 2026-05-31T23:59 — Fix Zephyr CMake source filename casing
+- **Author**: Oz
+- **Type**: fix
+- **REQs affected**: REQ-BUILD-001, REQ-ARCH-016
+- **Summary**: Updated root and subsystem CMake source references from
+  legacy uppercase filenames (`ARBITER_*.c`) to the actual lowercase
+  repository filenames (`arbiter_*.c`). This fixes Twister CMake generate
+  failures on Linux case-sensitive filesystems.
+- **Status**: complete
+
 ## 2026-05-31T23:44 — Fix Zephyr module CMake source path resolution
 - **Author**: Oz
 - **Type**: fix

subsys/arbiter/CMakeLists.txt

@@ -2,6 +2,6 @@
 
 zephyr_library()
 
-zephyr_library_sources_ifdef(CONFIG_ARBITER_SHELL ARBITER_shell.c)
-zephyr_library_sources_ifdef(CONFIG_ARBITER_RUNTIME_THREAD ARBITER_runtime_thread.c)
-zephyr_library_sources_ifdef(CONFIG_ARBITER_WATCHDOG ARBITER_watchdog.c)
+zephyr_library_sources_ifdef(CONFIG_ARBITER_SHELL arbiter_shell.c)
+zephyr_library_sources_ifdef(CONFIG_ARBITER_RUNTIME_THREAD arbiter_runtime_thread.c)
+zephyr_library_sources_ifdef(CONFIG_ARBITER_WATCHDOG arbiter_watchdog.c)