feat: bind evidence trees to registry revisions

backend/src/workspaces/registry.ts

@@ -387,6 +387,9 @@ export class WorkspaceRegistry {
       }
       if (request.action === "create" && existing) throw await this.conflictFor(request, status.head!, existing, local);
       if (request.action !== "create" && !existing) throw await this.conflictFor(request, status.head!, existing, local);
+      if (request.action !== "delete") {
+        await this.assertEvidenceContext(request.workspace, status.head!);
+      }
 
       const yamlPath = workspacePath(id);
       const docPaths = this.documentationPaths(id);
@@ -472,6 +475,20 @@ export class WorkspaceRegistry {
     ));
   }
 
+  private async assertEvidenceContext(workspace: WorkspaceDescriptor, revision: string): Promise<void> {
+    if (!isCanonicalWorkspace(workspace)) return;
+    if (workspace.evidence?.source.type !== "filesystem") return;
+    // P6 owns recursive containment. Here we deliberately validate only the declared root object.
+    await this.repository.assertTreeAtRevision(revision, workspace.evidence.source.uri);
+  }
+
+  private async assertSnapshotEvidenceContexts(state: ActiveState): Promise<void> {
+    for (const revision of state.revisions) {
+      const workspace = parseWorkspaceYaml(await readFile(revision.snapshotPath, "utf8"));
+      await this.assertEvidenceContext(workspace, revision.commit);
+    }
+  }
+
   private async activate(commit: string): Promise<void> {
     const safeHead = safeCommit(commit);
     const files = await this.repository.workspacePaths();
@@ -495,6 +512,7 @@ export class WorkspaceRegistry {
         if (workspace.workspace.id !== id) {
           throw new WorkspaceRegistryError("workspace_invalid", "Workspace ID does not match its repository path");
         }
+        await this.assertEvidenceContext(workspace, safeHead);
         let snapshotSource = source;
         const state: WorkspaceRevision["state"] = isCanonicalWorkspace(workspace)
           ? "operational"
@@ -721,6 +739,7 @@ export class WorkspaceRegistry {
         `${revision.id}.yaml`, `${revision.id}.env.example`, `${revision.id}.md`,
       ]);
       await this.assertManifestFiles(directory, manifest.files, legacyExpected);
+      await this.assertSnapshotEvidenceContexts(state);
       const expected = this.expectedSnapshotFiles(state);
       const files = Object.fromEntries(expected.map((name) => [name, manifest.files[name]]));
       await this.writeSnapshotManifest(directory, { ...state, files });
@@ -757,6 +776,7 @@ export class WorkspaceRegistry {
         throw new Error("manifest revisions do not match active state");
       }
       await this.assertManifestFiles(directory, manifest.files, this.expectedSnapshotFiles(state));
+      await this.assertSnapshotEvidenceContexts(state);
     } catch (error) {
       if (error instanceof WorkspaceRegistryError) throw error;
       throw new WorkspaceRegistryError("workspace_invalid", "Workspace snapshot integrity check failed");