feat: implement Tier 3 features — lane queue, credential redaction, token dashboard, xAI, Voyage AI

- Lane Queue: per-session FIFO queue in gateway replacing reject-when-busy (9 tests)
- Credential Redaction: redactConfig() expanded to cover 18+ secret fields (16 tests)
- Web UI Token Dashboard: system.tokenUsage endpoint + Usage page with summary cards
- xAI (Grok) Provider: OpenAI-compatible client with model pricing
- Voyage AI Embeddings: new embedding provider with configurable dimensions (5 tests)
- Update gap analysis: 90→95 match (70%→74%), Tier 3 section marked DONE
- Update state.json: test count 1001→1034, add tier3_completion entry

Total: 1034 tests passing across 85 files, typecheck clean

src/memory/embeddings.test.ts

@@ -5,6 +5,7 @@ import {
   GeminiEmbeddingProvider,
   OllamaEmbeddingProvider,
   LlamaCppEmbeddingProvider,
+  VoyageAIEmbeddingProvider,
 } from './embeddings.js';
 import type { EmbeddingConfig } from '../config/schema.js';
 
@@ -39,6 +40,11 @@ describe('createEmbeddingProvider', () => {
     expect(provider).toBeInstanceOf(LlamaCppEmbeddingProvider);
   });
 
+  it('creates Voyage provider', () => {
+    const provider = createEmbeddingProvider({ ...baseConfig, provider: 'voyage' });
+    expect(provider).toBeInstanceOf(VoyageAIEmbeddingProvider);
+  });
+
   it('throws on unknown provider', () => {
     expect(() => createEmbeddingProvider({ ...baseConfig, provider: 'unknown' as never })).toThrow('Unknown embedding provider');
   });
@@ -157,3 +163,67 @@ describe('LlamaCppEmbeddingProvider', () => {
     expect(provider.dimensions).toBe(768);
   });
 });
+
+describe('VoyageAIEmbeddingProvider', () => {
+  it('defaults to 1024 dimensions', () => {
+    const config: EmbeddingConfig = {
+      enabled: true,
+      provider: 'voyage',
+      model: 'voyage-3',
+      chunk_size: 512,
+      chunk_overlap: 50,
+      top_k: 5,
+      hybrid_weight: 0.7,
+    };
+    const provider = new VoyageAIEmbeddingProvider(config);
+    expect(provider.dimensions).toBe(1024);
+  });
+
+  it('reports configured dimensions', () => {
+    const config: EmbeddingConfig = {
+      enabled: true,
+      provider: 'voyage',
+      model: 'voyage-3-lite',
+      dimensions: 512,
+      chunk_size: 512,
+      chunk_overlap: 50,
+      top_k: 5,
+      hybrid_weight: 0.7,
+    };
+    const provider = new VoyageAIEmbeddingProvider(config);
+    expect(provider.dimensions).toBe(512);
+  });
+
+  it('uses custom endpoint if provided', () => {
+    const config: EmbeddingConfig = {
+      enabled: true,
+      provider: 'voyage',
+      model: 'voyage-3',
+      endpoint: 'https://custom.proxy.example.com/v1',
+      api_key: 'test-key',
+      chunk_size: 512,
+      chunk_overlap: 50,
+      top_k: 5,
+      hybrid_weight: 0.7,
+    };
+    // Should not throw when constructing with custom endpoint
+    const provider = new VoyageAIEmbeddingProvider(config);
+    expect(provider.dimensions).toBe(1024);
+  });
+
+  it('uses api_key from config', () => {
+    const config: EmbeddingConfig = {
+      enabled: true,
+      provider: 'voyage',
+      model: 'voyage-3',
+      api_key: 'voy-test-key-123',
+      chunk_size: 512,
+      chunk_overlap: 50,
+      top_k: 5,
+      hybrid_weight: 0.7,
+    };
+    // Should construct without error when api_key is provided
+    const provider = new VoyageAIEmbeddingProvider(config);
+    expect(provider.dimensions).toBe(1024);
+  });
+});