fix(server): open one transaction per delivery-policy entry point

#1517 added a rule that a @transactional method may not be reached by
self-invocation, because the call never passes the proxy and the inner annotation
is decorative. Both classes this branch adds broke it seven times: the convenience
overloads of the coverage service and the delivery policy delegated to each other,
so only the outermost annotation ever took effect.

Each public entry point now opens its own read-only transaction and goes straight
to a private implementation that assumes one. Behaviour is unchanged — the reads
were already running inside the outer transaction — but the annotations now say
what actually happens.

The same merge made the two policy entry points public, which is what makes their
@transactional apply at all.

Author: FelixTJDietrich

server/src/main/java/de/tum/cit/aet/hephaestus/agent/handler/PracticeFeedbackDeliveryPolicy.java

@@ -78,7 +78,7 @@ public class PracticeFeedbackDeliveryPolicy {
 
     @Transactional(readOnly = true)
     public Decision<Issue> evaluateIssue(AgentJob job) {
-        return evaluateIssue(job, DeliveryPolicyStage.AUTOMATIC, null);
+        return evaluateIssue(job, DeliveryPolicyStage.AUTOMATIC, null, DeliveryPolicySurface.ARTIFACT, Set.of());
     }
 
     @Transactional(readOnly = true)
@@ -191,11 +191,15 @@ private Decision<Issue> evaluateIssue(
 
     @Transactional(readOnly = true)
     public Decision<PullRequest> evaluatePullRequest(AgentJob job) {
-        return evaluatePullRequest(job, DeliveryPolicyStage.AUTOMATIC, null);
+        return evaluatePullRequest(job, DeliveryPolicyStage.AUTOMATIC, null, DeliveryPolicySurface.ARTIFACT, Set.of());
     }
 
     @Transactional(readOnly = true)
-    public Decision<PullRequest> evaluatePullRequest(AgentJob job, DeliveryPolicyStage stage, @Nullable UUID feedbackId) {
+    public Decision<PullRequest> evaluatePullRequest(
+        AgentJob job,
+        DeliveryPolicyStage stage,
+        @Nullable UUID feedbackId
+    ) {
         return evaluatePullRequest(job, stage, feedbackId, DeliveryPolicySurface.ARTIFACT, Set.of());
     }
 

server/src/main/java/de/tum/cit/aet/hephaestus/practices/review/PracticeReviewCoverageService.java

@@ -41,6 +41,10 @@ public class PracticeReviewCoverageService {
 
     @Transactional(readOnly = true)
     public WorkspaceReviewScope scope(Workspace workspace) {
+        return readScope(workspace);
+    }
+
+    private WorkspaceReviewScope readScope(Workspace workspace) {
         long workspaceId = workspace.getId();
         List<PracticeReviewRepositoryTarget> targets = repositoryTargetRepository.findByWorkspaceId(workspaceId);
         Map<Long, RepositoryToMonitor> monitorsById = monitorRepository
@@ -78,7 +82,7 @@ public WorkspaceReviewScope scope(Workspace workspace) {
 
     @Transactional(readOnly = true)
     public PracticeReviewCoverageSummaryDTO summary(Workspace workspace, int recentReviewVolume) {
-        return summary(workspace, scope(workspace), recentReviewVolume);
+        return summary(workspace, readScope(workspace), recentReviewVolume);
     }
 
     @Transactional(readOnly = true)
@@ -88,7 +92,7 @@ public PracticeReviewCoveragePreviewDTO preview(
         int recentReviewVolume
     ) {
         validate(workspace.getId(), proposed);
-        WorkspaceReviewScope current = scope(workspace);
+        WorkspaceReviewScope current = readScope(workspace);
         return new PracticeReviewCoveragePreviewDTO(
             summary(workspace, current, recentReviewVolume),
             summary(workspace, proposed, recentReviewVolume),
@@ -186,7 +190,7 @@ public boolean admits(
         String baseBranch,
         ReviewSubject subject
     ) {
-        return admits(workspace, repositoryNameWithOwner, baseBranch, subject, true);
+        return readAssessment(workspace, repositoryNameWithOwner, baseBranch, subject, true).admitted();
     }
 
     @Transactional(readOnly = true)
@@ -197,7 +201,13 @@ public boolean admits(
         ReviewSubject subject,
         boolean branchRestrictionsApply
     ) {
-        return assess(workspace, repositoryNameWithOwner, baseBranch, subject, branchRestrictionsApply).admitted();
+        return readAssessment(
+            workspace,
+            repositoryNameWithOwner,
+            baseBranch,
+            subject,
+            branchRestrictionsApply
+        ).admitted();
     }
 
     @Transactional(readOnly = true)
@@ -208,7 +218,17 @@ public CoverageAssessment assess(
         ReviewSubject subject,
         boolean branchRestrictionsApply
     ) {
-        WorkspaceReviewScope scope = scope(workspace);
+        return readAssessment(workspace, repositoryNameWithOwner, baseBranch, subject, branchRestrictionsApply);
+    }
+
+    private CoverageAssessment readAssessment(
+        Workspace workspace,
+        String repositoryNameWithOwner,
+        String baseBranch,
+        ReviewSubject subject,
+        boolean branchRestrictionsApply
+    ) {
+        WorkspaceReviewScope scope = readScope(workspace);
         SubjectStatus subjectStatus;
         if (subject == null || subject.actorId() == null) {
             subjectStatus = SubjectStatus.MISSING;