API V3: Implement Structured Error Handling and Validation Tests

- Updated api_get_object and api_post_object to extract rich metadata (meta.details) from 400/500 responses.
- Enables frontend to bubble up specific DB schema, validation, and constraint errors for better debugging.
- Added 'V3 Hardening' section to /testing dashboard with automated tests for Permissive Mode and Structured Error extraction.

src/lib/ae_api/api_get_object.ts

@@ -184,7 +184,21 @@ export const get_object = async function get_object({
                     return false;
                 }
 
-                console.log('The response was not ok. Throwing an error!');
+                // Structured Error Handling (V3): Attempt to get rich error metadata
+                let error_json: any = null;
+                try {
+                    error_json = await response.json();
+                } catch (e) {
+                    // Not JSON
+                }
+
+                if (log_lvl) console.log('The response was not ok. Structured Error Check:', error_json);
+                
+                if (error_json?.meta?.details) {
+                    // Return the rich error object so caller can handle specific categories (database_schema, etc)
+                    return error_json; 
+                }
+
                 throw new Error(`HTTP error! status: ${response.status}`);
             }