fix(tests): enhance system settings tests with feature flag propagation and retry logic

- Added initial feature flag state verification before tests to ensure a stable starting point.
- Implemented retry logic with exponential backoff for toggling feature flags, improving resilience against transient failures.
- Introduced `waitForFeatureFlagPropagation` utility to replace hard-coded waits with condition-based verification for feature flag states.
- Added advanced test scenarios for handling concurrent toggle operations and retrying on network failures.
- Updated existing tests to utilize the new retry and propagation utilities for better reliability and maintainability.

docs/plans/current_spec.md.backup

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+# Playwright E2E Test Timeout Fix - Feature Flags Endpoint
+
+## 1. Introduction
+
+### Overview
+This plan addresses systematic timeout failures in Playwright E2E tests for the feature flags endpoint (`/feature-flags`) occurring consistently in CI environments. The tests in `tests/settings/system-settings.spec.ts` are failing due to timeouts when waiting for API responses during feature toggle operations.
+
+### Problem Statement
+Four tests are timing out in CI:
+1. `should toggle Cerberus security feature`
+2. `should toggle CrowdSec console enrollment`
+3. `should toggle uptime monitoring`
+4. `should persist feature toggle changes`
+
+All tests follow the same pattern:
+- Click toggle → Wait for PUT `/feature-flags` (currently 15s timeout)
+- Wait for subsequent GET `/feature-flags` (currently 10s timeout)
+- Both operations frequently exceed their timeouts in CI
+
+### Root Cause Analysis
+Based on comprehensive research, the timeout failures are caused by:
+
+1. **Backend N+1 Query Pattern** (PRIMARY)
+   - `GetFlags()` makes 3 separate SQLite queries (one per feature flag)
+   - `UpdateFlags()` makes additional individual queries per flag
+   - Each toggle operation requires: 3 queries (PUT) + 3 queries (GET) = 6 DB operations minimum
+
+2. **CI Environment Characteristics**
+   - Slower disk I/O compared to local development
+   - SQLite on CI runners lacks shared memory optimizations
+   - No database query caching layer
+   - Sequential query execution compounds latency
+
+3. **Test Pattern Amplification**
+   - Tests explicitly set lower timeouts (15s, 10s) than helper defaults (30s)
+   - Immediate GET after PUT doesn't allow for state propagation
+   - No retry logic for transient failures
+
+### Objectives
+1. **Immediate**: Increase timeouts and add strategic waits to fix CI failures
+2. **Short-term**: Improve test reliability with better wait strategies
+3. **Long-term**: Document backend performance optimization opportunities