feat(core): update backend refactoring specs, add analysis tools, and fix gemini retry

Author: Mateusz

.kiro/specs/backend-service-refactoring/design.md

@@ -63,16 +63,18 @@ This document specifies the requirements for refactoring the `BackendService` cl
 
 **User Story:** As a developer, I want the refactored code to maintain full test coverage, so that I can be confident the refactoring introduces no regressions.
 
-#### Acceptance Criteria
-
-1. WHEN the refactoring is complete THEN the system SHALL pass all existing unit tests without modification
-2. WHEN the refactoring is complete THEN the system SHALL pass all existing integration tests without modification
-3. WHEN new services are created THEN the system SHALL include unit tests for each new service
-4. WHEN the refactoring is complete THEN the test suite SHALL achieve zero test failures
-
-### Requirement 5
-
-**User Story:** As a developer, I want the stream formatting logic to be isolated, so that SSE encoding and chunk validation can be tested and modified independently.
+#### Acceptance Criteria
+
+1. WHEN the refactoring is complete THEN the system SHALL pass all existing unit tests without modification
+2. WHEN the refactoring is complete THEN the system SHALL pass all existing integration tests without modification
+3. WHEN new services are created THEN the system SHALL include unit tests for each new service
+4. WHEN the refactoring is complete THEN the test suite SHALL achieve zero test failures
+5. WHEN responsibilities are extracted THEN BackendService SHALL retain existing helper/private methods with compatible signatures (e.g., `_stream_as_sse_bytes`, `_wrap_stream_for_usage`, `_apply_model_aliases`, `_apply_reasoning_config`, `_apply_uri_parameters`, planning phase helpers, lifecycle helpers, `_normalize_provider_exception`) as thin delegating wrappers so existing tests and scripts do not require changes
+6. WHEN helpers are delegated to extracted services THEN those services SHALL preserve the observable invariants documented in Design → “Invariants and Gotchas to Preserve”
+
+### Requirement 5
+
+**User Story:** As a developer, I want the stream formatting logic to be isolated, so that SSE encoding and chunk validation can be tested and modified independently.
 
 #### Acceptance Criteria
 

.kiro/specs/backend-service-refactoring/requirements.md

@@ -0,0 +1,29 @@
+{
+  "featureName": "backend-service-refactoring",
+  "createdAt": "2025-12-12T00:00:00.000Z",
+  "updatedAt": "2025-12-12T00:00:00.000Z",
+  "status": "approved",
+  "phases": {
+    "requirements": {
+      "status": "approved",
+      "file": "requirements.md"
+    },
+    "design": {
+      "status": "approved",
+      "file": "design.md"
+    },
+    "tasks": {
+      "status": "approved",
+      "file": "tasks.md"
+    }
+  },
+  "summary": {
+    "description": "Refactor BackendService God Object into focused, single-responsibility services following SOLID principles",
+    "totalTasks": 16,
+    "totalSubtasks": 47,
+    "newInterfaces": 8,
+    "newServices": 8,
+    "propertyTests": 14,
+    "checkpoints": 3
+  }
+}