feat: use actual project data, real usage examples, dry-run/verbose flags, skip-unchanged optimization

- renderer: render_architecture_md accepts Config, uses project name and current date
- renderer: generate real Python usage examples from analyzed symbols
- writer: skip writing files when content unchanged (optimization)
- cli: add --dry-run flag to generate command (lists files without writing)
- cli: add verbose logging for file/module/symbol generation progress

archdoc-core/src/writer.rs

@@ -70,17 +70,13 @@ impl DiffAwareWriter {
             // Check if content has changed
             let content_changed = existing_content != new_content;
             
-            // Write updated content
+            // Only write if content actually changed (optimization)
             if content_changed {
                 let updated_content = self.update_timestamp(new_content)?;
                 fs::write(file_path, updated_content)
                     .map_err(ArchDocError::Io)?;
-            } else {
-                // Content hasn't changed, but we might still need to update timestamp
-                // TODO: Implement timestamp update logic based on config
-                fs::write(file_path, new_content)
-                    .map_err(ArchDocError::Io)?;
             }
+            // If not changed, skip writing entirely
         }
         
         Ok(())
@@ -118,17 +114,13 @@ impl DiffAwareWriter {
             // Check if content has changed
             let content_changed = existing_content != new_content;
             
-            // Write updated content
+            // Only write if content actually changed (optimization)
             if content_changed {
                 let updated_content = self.update_timestamp(new_content)?;
                 fs::write(file_path, updated_content)
                     .map_err(ArchDocError::Io)?;
-            } else {
-                // Content hasn't changed, but we might still need to update timestamp
-                // TODO: Implement timestamp update logic based on config
-                fs::write(file_path, new_content)
-                    .map_err(ArchDocError::Io)?;
             }
+            // If not changed, skip writing entirely
         } else {
             eprintln!("Warning: No symbol marker found for {} in {}", symbol_id, file_path.display());
         }