refactor: simplify PKI module naming and struct names

- Rename modules: identity_auth → identity, approval_workflow → approval
- Simplify struct names in identity module:
  * IdentityContext → Context
  * VerificationCredential → Credential
  * VerificationCredentials → Credentials
  * AuthResult → AuthOutcome (avoid Rust Result conflict)
  * TrustPolicy → Policy
  * TrustEvaluator → Evaluator
- Simplify struct names in approval module:
  * WorkflowState → State
  * ApprovalWorkflow → Workflow
- Simplify struct names in validation module:
  * ValidationIssue → Issue
  * ValidationResult → ValidationOutcome
  * ValidationPolicy → Policy
- Add backward compatibility type aliases for all renamed structs
- All 44 tests passing after refactoring

🤖 Generated with [Claude Code](https://claude.ai/code)

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

Author: atlas-form

crates/capsula-pki/src/error.rs

@@ -87,6 +87,10 @@ pub enum PkiError {
     #[error("Key error: {0}")]
     KeyError(String),
 
+    /// 身份认证错误
+    #[error("Authentication error: {0}")]
+    AuthError(String),
+
     /// IO错误
     #[error("IO error: {0}")]
     IoError(#[from] std::io::Error),

…/capsula-pki/src/ra/approval_workflow.rs crates/capsula-pki/src/ra/approval.rscrates/capsula-pki/src/ra/approval_workflow.rs renamed to crates/capsula-pki/src/ra/approval.rs crates/capsula-pki/src/ra/approval_workflow.rs renamed to crates/capsula-pki/src/ra/approval.rs

@@ -2,12 +2,11 @@
 //!
 //! 提供手动/自动审批流程控制
 
-use crate::error::Result;
-use crate::ra::identity_auth::AuthResult;
+use crate::ra::identity::AuthOutcome;
 
 /// 工作流状态
 #[derive(Debug, Clone, PartialEq)]
-pub enum WorkflowState {
+pub enum State {
     /// 待审批
     Pending,
     /// 审批通过
@@ -17,12 +16,12 @@ pub enum WorkflowState {
 }
 
 /// 审批工作流
-pub struct ApprovalWorkflow {
+pub struct Workflow {
     /// 自动审批阈值
     auto_approval_threshold: u8,
 }
 
-impl ApprovalWorkflow {
+impl Workflow {
     /// 创建新的审批工作流
     pub fn new(auto_approval_threshold: u8) -> Self {
         Self {
@@ -31,13 +30,17 @@ impl ApprovalWorkflow {
     }
 
     /// 评估是否可以自动审批
-    pub fn evaluate(&self, auth_result: &AuthResult) -> WorkflowState {
+    pub fn evaluate(&self, auth_result: &AuthOutcome) -> State {
         if auth_result.trust_level >= self.auto_approval_threshold {
-            WorkflowState::Approved
+            State::Approved
         } else if auth_result.trust_level < 30 {
-            WorkflowState::Rejected
+            State::Rejected
         } else {
-            WorkflowState::Pending
+            State::Pending
         }
     }
-}
+}
+
+// 重新导出为旧名称以保持向后兼容
+pub type WorkflowState = State;
+pub type ApprovalWorkflow = Workflow;