Refactor CMake and VSCode settings; add Day 4 solution

- Updated .vscode/settings.json to enhance Clangd configuration and disable IntelliSense.
- Removed obsolete Clang-Format and Clang-Tidy tasks from .vscode/tasks.json.
- Modified CMakeLists.txt to enable compile commands export and adjusted target properties for Day 4.
- Added new CMakeLists.txt and main.cpp for Day 4 solution, implementing diagram parsing and movable paper counting logic.
- Included test_input and puzzle_input files for Day 4.
- Deleted the run-clang-tidy.sh script as it is no longer needed.

.clang-tidy

@@ -1,4 +1,18 @@
-Checks: '-*,modernize-*,readability-*,bugprone-*,performance-*'
+# We explicitly enable checks with '*' and disable noisy ones with '-'
+Checks: >
+  -*,
+  bugprone-*,
+  modernize-*,
+  performance-*,
+  readability-*,
+  cppcoreguidelines-*,
+  misc-*,
+  # Disable these specifically if they are too annoying
+  -modernize-use-trailing-return-type,
+  -llvmlibc-*
+
+# Treat warnings as errors (optional, good for strict discipline)
 WarningsAsErrors: ''
-HeaderFilterRegex: '.*'
-FormatStyle: file
+
+# This ensures clang-tidy sees the same headers as your compiler
+# It will read the compile_commands.json automatically