refactor: consolidate ErrorSeverity to common crate

Three duplicate ErrorSeverity enums (data/error.rs, data/validation.rs,
database/error.rs) with variants Low/Medium/High/Critical now use the
canonical definition in common::error::ErrorSeverity.

Extended common's ErrorSeverity with Low, Medium, High variants (alongside
existing Debug, Info, Warn, Error, Critical) and added PartialOrd/Ord derives
so both severity models coexist in a single type.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

crates/common/src/error.rs

@@ -127,15 +127,21 @@ impl fmt::Display for ErrorCategory {
 }
 
 /// Error severity levels for prioritization and alerting
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Serialize, Deserialize)]
 #[allow(clippy::module_name_repetitions)]
 pub enum ErrorSeverity {
     /// Debug level - for development and troubleshooting
     Debug,
+    /// Low severity - informational errors (alias for Info)
+    Low,
     /// Info level - informational messages
     Info,
+    /// Medium severity - recoverable errors (alias for Warn)
+    Medium,
     /// Warning level - potentially problematic situations
     Warn,
+    /// High severity - significant errors requiring attention (alias for Error)
+    High,
     /// Error level - error conditions that should be addressed
     Error,
     /// Critical level - serious error conditions requiring immediate attention
@@ -146,8 +152,11 @@ impl fmt::Display for ErrorSeverity {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self {
             Self::Debug => write!(f, "DEBUG"),
+            Self::Low => write!(f, "LOW"),
             Self::Info => write!(f, "INFO"),
+            Self::Medium => write!(f, "MEDIUM"),
             Self::Warn => write!(f, "WARN"),
+            Self::High => write!(f, "HIGH"),
             Self::Error => write!(f, "ERROR"),
             Self::Critical => write!(f, "CRITICAL"),
         }

crates/data/src/error.rs

@@ -1,6 +1,6 @@
 //! Error types for the data module
 
-use std::fmt;
+pub use common::error::ErrorSeverity;
 use thiserror::Error;
 
 /// Result type alias for data module operations
@@ -436,29 +436,7 @@ impl DataError {
     }
 }
 
-/// Error severity levels
-#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
-pub enum ErrorSeverity {
-    /// Low severity - informational errors
-    Low,
-    /// Medium severity - recoverable errors
-    Medium,
-    /// High severity - significant errors requiring attention
-    High,
-    /// Critical severity - system-threatening errors
-    Critical,
-}
-
-impl fmt::Display for ErrorSeverity {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self {
-            Self::Low => write!(f, "LOW"),
-            Self::Medium => write!(f, "MEDIUM"),
-            Self::High => write!(f, "HIGH"),
-            Self::Critical => write!(f, "CRITICAL"),
-        }
-    }
-}
+// ErrorSeverity is imported from common::error
 
 #[cfg(test)]
 mod tests {

crates/data/src/validation.rs

@@ -107,14 +107,8 @@ pub enum ValidationWarningType {
     InfrequentUpdates,
 }
 
-/// Error severity levels
-#[derive(Debug, Clone, Serialize, Deserialize)]
-pub enum ErrorSeverity {
-    Low,
-    Medium,
-    High,
-    Critical,
-}
+// ErrorSeverity is imported from common::error (re-exported below)
+pub use common::error::ErrorSeverity;
 
 /// Data quality metrics
 #[derive(Debug, Clone, Serialize, Deserialize)]

crates/database/src/error.rs

@@ -1,4 +1,4 @@
-use std::fmt;
+pub use common::error::ErrorSeverity;
 use thiserror::Error;
 
 /// Database error types covering all database operations
@@ -114,25 +114,7 @@ impl DatabaseError {
     }
 }
 
-/// Error severity levels
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-pub enum ErrorSeverity {
-    Low,
-    Medium,
-    High,
-    Critical,
-}
-
-impl fmt::Display for ErrorSeverity {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self {
-            ErrorSeverity::Low => std::write!(f, "LOW"),
-            ErrorSeverity::Medium => std::write!(f, "MEDIUM"),
-            ErrorSeverity::High => std::write!(f, "HIGH"),
-            ErrorSeverity::Critical => write!(f, "CRITICAL"),
-        }
-    }
-}
+// ErrorSeverity is imported from common::error
 
 /// Convert SQLx errors to our domain errors
 impl From<sqlx::Error> for DatabaseError {