feat: add adaptive cache invalidation hooks for transaction state

[dinahmaccodes]

PR Description

Backend: Adaptive Cache Invalidation Hooks (#637)

Implemented a hook-based system for triggering targeted cache invalidation when writes change dependent read models. The system allows registering invalidation hooks that return cache key patterns to clear based on transaction events.

Changes:

• Added registerInvalidationHook() and triggerCacheInvalidation() to cache middleware
• Registered hooks for transaction state changes (deposits/withdrawals)
• Updated vault endpoints to trigger invalidation via hooks instead of manual calls
• Maintains backwards compatibility with existing cache behavior

Backend: Redis-Backed Adaptive Throttle (#862)

Enhanced the adaptive throttle middleware to use Redis for distributed state when REDIS_URL is configured, enabling throttling to work across multiple backend instances.

Changes:

• Created RedisAbuseStore class that falls back to in-memory storage when Redis is unavailable
• Added async/await pattern for Redis operations with error handling
• Integrated with existing redisClientManager from rate limiter
• Added throttle metrics: adaptive_throttle_block_count and adaptive_throttle_active_blocks
• Maintains in-memory fallback for local/test environments with startup warning

Backend: Retry Budget Limits for RPC Dependencies (#630)

Introduced configurable retry budget controls to prevent runaway retries under upstream Soroban RPC failures.

Changes:

• Created RetryBudgetService with configurable limits (max retries, window, success rate, failure threshold)
• Integrated retry budget into sorobanClient.ts with exponential backoff
• Added retryWithBudget() helper that respects budget limits
• Environment variables: RETRY_BUDGET_MAX_RETRIES, RETRY_BUDGET_WINDOW_MS, RETRY_BUDGET_MIN_SUCCESS_RATE, RETRY_BUDGET_FAILURE_THRESHOLD
• Automatic success/failure tracking and budget enforcement

Frontend: Cross-Page Toast Center with Deduplication (#619)

Enhanced the toast notification system with deduplication to prevent showing identical toasts multiple times.

Changes:

• Added dedupeKey option to ToastOptions for custom deduplication
• Automatic deduplication based on title+description+variant within 3-second window
• Added clearAll() method to dismiss all toasts
• Periodic cleanup of stale deduplication entries
• Maintains consistent severity styles across pages

---

Checklist

• Adaptive cache invalidation hooks implemented
• Redis-backed adaptive throttle state added
• Retry budget limits for RPC dependencies implemented
• Cross-page toast center with deduplication added
• Backwards compatibility maintained for all changes
• Proper error handling and fallbacks implemented
• Environment variable configuration added where appropriate

---

Closes #637
Closes #862
Closes #630
Closes #619

[drips-wave]

@dinahmaccodes Great news! 🎉 Based on an automated assessment of this PR, the linked Wave issue(s) no longer count against your application limits.

You can now already apply to more issues while waiting for a review of this PR. Keep up the great work! 🚀

Learn more about application limits

[dinahmaccodes]

@Junirezz
please review maintainer