feat: initial commit for ud maintenance utility

- Add C source code for Debian apt update, autoremove, and cleanup tasks
- Add Makefile with build, install, uninstall, and clean targets
- Add README.md with build and usage instructions
- Add MIT license and .gitignore for build artifacts

1 files changed, 36 insertions, 0 deletions

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+# ud
+
+A clean, minimalist, robust C utility designed to automate Debian-based Linux system maintenance tasks. It manages `apt` package list updates, performs conditional upgrades, purges orphaned dependencies, clears package caches, and cleans local user thumbnail and screenshot caches.
+
+## Features
+
+- **Automated APT Maintenance:** Updates repository indices, checks for upgradeable packages, and runs `apt full-upgrade` only when updates exist.
+- **Dependency & Cache Cleanup:** Automatically purges unused dependencies and lingering configuration files (`apt autoremove --purge`) and empties cached installer packages (`apt clean`).
+- **User Cache Housekeeping:** Safely cleans desktop thumbnail caches and user screenshot directories without failing if the directories are empty.
+- **Robust POSIX C Implementation:** Built using strict standard C (`-std=c11`, POSIX 2008) with explicit bounds checking on formatted buffers and process status checking (`WIFEXITED`, `WEXITSTATUS`).
+- **Clean Terminal Output:** Indents subprocess output using `sed` for a clear, readable terminal log.
+
+---
+
+## Prerequisites & Dependencies
+
+This utility requires a **Debian-based distribution** (Debian, Ubuntu, Linux Mint, Pop!_OS, etc.) with the following installed:
+
+- `gcc` or `clang`
+- `make`
+- `apt`
+- `sed`
+- `sudo` privileges for package management operations
+
+---
+
+## Build Instructions
+
+To compile the executable using `make`:
+
+```bash
+# Build the utility (uses gcc with -Wall -Wextra -Wpedantic -O2 -std=c11)
+make
+
+# Clean build artifacts
+make clean