Cache settings fetched in started() of OmnichannelTranscript to avoid repeated fetches

Problem

Multiple runtime settings are fetched via Promise.all inside started() of OmnichannelTranscript , with a // TODO: cache these with mem comment.
This causes repeated network/database calls on each startup or reload.

Impact

• Increased latency at startup
• Unnecessary load on settings service
• Potential rate-limit or performance regressions under heavy restarts

Suggested Fix

Implement a simple cache for these settings (use the existing mem/cache service if available, or an in-memory cache with TTL):

1. On started(), read from cache first.
2. On cache miss, fetch with Promise.all, then store results in cache with a reasonable TTL .
3. Provide a cache key namespace scoped to OmnichannelTranscript.
4. Add fallback: if cache read/write fails, continue to fetch (no breaking change).

Tests

• Unit test verifying settings are read from cache when present
• Integration/manual test showing reduced calls to settings service across repeated starts
• No behavioral change if cache is empty or fails

Start at OmnichannelTranscript's started() method and inspect the existing mem/cache service, along with the Promise.all settings fetch described in the issue. Add tests covering cache hits, empty or failed caches, and repeated starts, then verify that settings-service calls are reduced without changing behavior.