feat: Add unified LiteLLM API management with dashboard UI and CLI integration

- Create ccw-litellm Python package with AbstractEmbedder and AbstractLLMClient interfaces
- Add BaseEmbedder abstraction and factory pattern to codex-lens for pluggable backends
- Implement API Settings dashboard page for provider credentials and custom endpoints
- Add REST API routes for CRUD operations on providers and endpoints
- Extend CLI with --model parameter for custom endpoint routing
- Integrate existing context-cache for @pattern file resolution
- Add provider model registry with predefined models per provider type
- Include i18n translations (en/zh) for all new UI elements

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

codex-lens/src/codexlens/semantic/base.py

@@ -0,0 +1,51 @@
+"""Base class for embedders.
+
+Defines the interface that all embedders must implement.
+"""
+
+from __future__ import annotations
+
+from abc import ABC, abstractmethod
+from typing import Iterable
+
+import numpy as np
+
+
+class BaseEmbedder(ABC):
+    """Base class for all embedders.
+
+    All embedder implementations must inherit from this class and implement
+    the abstract methods to ensure a consistent interface.
+    """
+
+    @property
+    @abstractmethod
+    def embedding_dim(self) -> int:
+        """Return embedding dimensions.
+
+        Returns:
+            int: Dimension of the embedding vectors.
+        """
+        ...
+
+    @property
+    @abstractmethod
+    def model_name(self) -> str:
+        """Return model name.
+
+        Returns:
+            str: Name or identifier of the underlying model.
+        """
+        ...
+
+    @abstractmethod
+    def embed_to_numpy(self, texts: str | Iterable[str]) -> np.ndarray:
+        """Embed texts to numpy array.
+
+        Args:
+            texts: Single text or iterable of texts to embed.
+
+        Returns:
+            numpy.ndarray: Array of shape (n_texts, embedding_dim) containing embeddings.
+        """
+        ...