Implement bounded repository navigation with repo-lens

- Add map, find, and around commands with repository root discovery
- Stream literal ripgrep searches with match counts and result limits
- Add direct subprocess execution and explicit error returns
- Disable C++ exceptions and add navigation tests
- Support CMake installation and document builds and deployment
- Add a reusable agent skill and document skill discovery

test/CMakeLists.txt

@@ -3,11 +3,17 @@ include(gtest)
 add_executable(
   repo-lens-test
   test_main.cpp
+  navigation_test.cpp
+  ../src/navigation.cpp
+  ../src/process.cpp
+  ../src/repo_tool_around.cpp
+  ../src/repo_tool_find.cpp
+  ../src/repo_tool_map.cpp
 )
 
 target_link_libraries(
   repo-lens-test
-  gtest_main
+  gtest
 )
 
 if(ENABLE_ALL_REASONABLE_WARNINGS)
@@ -29,3 +35,6 @@ endif()
 
 include(GoogleTest)
 gtest_discover_tests(repo-lens-test)
+
+target_include_directories(repo-lens-test PRIVATE "${PROJECT_SOURCE_DIR}/include")
+target_compile_definitions(repo-lens-test PRIVATE REPO_TEST_EXECUTABLE="$<TARGET_FILE:repo-lens-test>")