feat: add corex-storage crate for unified storage abstraction

- Introduced corex-storage crate with support for local disk, S3-compatible, and Google Cloud Storage backends.
- Implemented StorageDriver trait for various storage backends.
- Added LocalFileStorage for local disk operations.
- Added S3Storage for S3-compatible object storage with multipart upload support.
- Added GcsStorage for Google Cloud Storage operations.
- Included error handling for storage operations.
- Added tests for each storage backend to ensure functionality.
- Created README.md for documentation and usage examples.
- Added Apache and MIT licenses for open-source compliance.

crates/mytheclipse-config/src/error.rs

@@ -0,0 +1,32 @@
+//! Shared error type for corex-config.
+
+/// Errors surfaced while loading or reloading configuration.
+#[non_exhaustive]
+#[derive(Debug)]
+pub enum ConfigError {
+    /// An I/O error reading a config source (file not found, permissions, ...).
+    Io(String),
+    /// A source could not be parsed (malformed YAML/JSON/TOML).
+    Parse(String),
+    /// The merged configuration could not be deserialized into the target type.
+    Deserialize(String),
+    /// The requested file extension has no registered loader (feature not
+    /// enabled, or unsupported format).
+    UnsupportedFormat(String),
+    /// Hot-reload setup failed (e.g. the file watcher could not be installed).
+    Watch(String),
+}
+
+impl std::fmt::Display for ConfigError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::Io(s) => write!(f, "config io error: {s}"),
+            Self::Parse(s) => write!(f, "config parse error: {s}"),
+            Self::Deserialize(s) => write!(f, "config deserialize error: {s}"),
+            Self::UnsupportedFormat(s) => write!(f, "unsupported config format: {s}"),
+            Self::Watch(s) => write!(f, "config watch error: {s}"),
+        }
+    }
+}
+
+impl std::error::Error for ConfigError {}