feat: add APIEmbedder for remote embedding with multi-endpoint support

- Introduced APIEmbedder class to handle embeddings via a remote HTTP API.
- Implemented token packing to optimize batch sizes based on token limits.
- Added support for multiple API endpoints with round-robin dispatching.
- Included retry logic for API calls with exponential backoff on failures.
- Enhanced indexing pipeline with file exclusion checks and smart chunking strategies.
- Updated tests to cover new APIEmbedder functionality and ensure robustness.

ccw/frontend/src/locales/en/codexlens.json

@@ -290,41 +290,31 @@
   "envGroup": {
     "embedding": "Embedding",
     "reranker": "Reranker",
-    "concurrency": "Concurrency",
-    "cascade": "Cascade Search",
-    "indexing": "Indexing",
-    "chunking": "Chunking"
+    "search": "Search Pipeline",
+    "indexing": "Indexing"
   },
   "envField": {
     "backend": "Backend",
     "model": "Model",
-    "autoEmbedMissing": "Auto Build Missing Vectors",
-    "useGpu": "Use GPU",
-    "highAvailability": "High Availability",
-    "loadBalanceStrategy": "Load Balance Strategy",
-    "rateLimitCooldown": "Rate Limit Cooldown",
-    "enabled": "Enabled",
+    "localModel": "Local Model",
+    "apiUrl": "API URL",
+    "apiKey": "API Key",
+    "multiEndpoints": "Multi-Endpoint",
+    "embedDim": "Embed Dimension",
+    "apiConcurrency": "Concurrency",
+    "maxTokensPerBatch": "Max Tokens/Batch",
+    "useGpu": "Device",
     "topKResults": "Top K Results",
-    "maxWorkers": "Max Workers",
     "batchSize": "Batch Size",
-    "dynamicBatchSize": "Dynamic Batch Size",
-    "batchSizeUtilization": "Utilization Factor",
-    "batchSizeMax": "Max Batch Size",
-    "charsPerToken": "Chars Per Token",
-    "searchStrategy": "Search Strategy",
-    "coarseK": "Coarse K",
-    "fineK": "Fine K",
-    "stagedStage2Mode": "Stage-2 Mode",
-    "stagedClusteringStrategy": "Clustering Strategy",
-    "stagedClusteringMinSize": "Cluster Min Size",
-    "enableStagedRerank": "Enable Rerank",
-    "useAstGrep": "Use ast-grep",
-    "staticGraphEnabled": "Static Graph",
-    "staticGraphRelationshipTypes": "Relationship Types",
-    "stripComments": "Strip Comments",
-    "stripDocstrings": "Strip Docstrings",
-    "testFilePenalty": "Test File Penalty",
-    "docstringWeight": "Docstring Weight"
+    "binaryTopK": "Binary Top K",
+    "annTopK": "ANN Top K",
+    "ftsTopK": "FTS Top K",
+    "fusionK": "Fusion K",
+    "codeAwareChunking": "Code-Aware Chunking",
+    "indexWorkers": "Index Workers",
+    "maxFileSize": "Max File Size (bytes)",
+    "hnswEf": "HNSW ef",
+    "hnswM": "HNSW M"
   },
   "install": {
     "title": "Install CodexLens",