feat(genome): resilient embedding batch pipeline with exponential backoff & circuit breaker

- New module src/genome/embedding-resilience.ts (~380 LOC):
  - Exponential backoff (3–15s range) with full jitter, configurable max attempts (default 3)
  - Per-backend circuit breaker with sliding window (10-req default), 50% failure threshold,
    30s open duration, half-open probe pattern; auto-reset on success
  - Fallback chain orchestration: skips open-breaker backends directly to next tier
  - Adaptive timeout scaling: Ollama >8s → reduce to 12s; Anthropic >3s → prefer local-ultrafast
  - Resilience profile persistence to .ashlrcode/genome/resilience-profile.jsonl
  - Per-(backend, querySizeBucket) latency histograms with p95 computation
  - PermanentEmbeddingError class; isPermanentError() guard (401/403 never retried)
  - resilientGenerateEmbeddingWithFallback() and resilientRouterEmbed() wrappers
  - EmbeddingResiliencePipeline class + createEmbeddingResiliencePipeline() factory
- src/genome/index.ts: export * from embedding-resilience.ts
- __tests__/embedding-resilience.test.ts (~440 LOC, 78 tests, all green):
  - classifyQuerySize, computeBackoffDelay, circuit breaker transitions,
    AdaptiveTimeoutTracker, pipeline embed, computeLatencyHistogram,
    JSONL persistence, genome/index.ts export coverage

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: masonwyatt23