feat: implemented base editing, underline and striking

engine/include/pdfengine/pdf_document.hpp

@@ -28,6 +28,25 @@ struct DocumentMetadata {
     std::string modificationDate;
 };
 
+// Encryption + permission state of a loaded document. Booleans are the EFFECTIVE
+// permissions for how the doc was opened (an owner-unlocked doc reports all true).
+// The engine only surfaces these — enforcement happens in the gateway/app layers.
+struct DocumentPermissions {
+    bool isEncrypted = false;
+    std::string encryption = "None"; // "None", "RC4-40", "RC4-128", "AES-128", "AES-256"
+    int securityRevision = -1;       // FPDF_GetSecurityHandlerRevision (-1 if unencrypted)
+    bool ownerUnlocked = false;      // encrypted but opened with full (owner) access
+
+    bool canPrint = true;
+    bool canPrintHighRes = true;
+    bool canModify = true;
+    bool canCopy = true;                  // extract text / graphics
+    bool canAnnotate = true;              // add/modify annotations
+    bool canFillForms = true;
+    bool canExtractForAccessibility = true;
+    bool canAssemble = true;              // insert / rotate / delete pages
+};
+
 struct PageImage {
     int width;
     int height;
@@ -214,6 +233,7 @@ public:
 
     [[nodiscard]] virtual int pageCount() const noexcept = 0;
     [[nodiscard]] virtual DocumentMetadata metadata() const noexcept = 0;
+    [[nodiscard]] virtual DocumentPermissions permissions() const noexcept = 0;
 
     // A single entry in the document outline (bookmarks), flattened with a depth level.
     struct OutlineItem {