fix: resolve OpenAI Compatible embedder provider save validation issue

[roomote]

This PR fixes the issue where the Save button would not work when configuring the OpenAI Compatible embedder provider in the Code Indexing settings.

Problem

Users reported that when trying to configure the "OpenAI Compatible" embedder provider, the Save button would not work. The user could fill in all required fields (Base URL, API Key, Model, Dimensions) but clicking Save would do nothing - no error message was shown and the settings were not saved.

Root Cause

The validation schema for the OpenAI Compatible provider required the codebaseIndexEmbedderModelDimension field to be a number ≥ 1, but the validation data preparation logic was not properly handling the conversion of string input values to numbers, causing validation to fail silently.

Solution

• Fixed the validation data preparation logic to properly convert string inputs to numbers for the model dimension field
• Ensured that validation errors are properly displayed to users when required fields are missing or invalid
• The validation schema now correctly handles the required model dimension field for OpenAI Compatible provider

Testing

• Verified that the Save button now works correctly for OpenAI Compatible provider
• Confirmed that validation errors are properly displayed when required fields are missing
• Ensured that other embedder providers (OpenAI, Ollama, Gemini) continue to work as expected

Fixes #5842

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Important

Fixes save button issue for OpenAI Compatible provider in CodeIndexPopover.tsx by correcting validation logic and ensuring error display.

• Behavior:
  • Fixes save button issue for OpenAI Compatible provider in CodeIndexPopover.tsx by correcting validation logic.
  • Converts codebaseIndexEmbedderModelDimension from string to number for validation.
  • Displays validation errors for missing or invalid fields.
• Validation:
  • Updates validation schema in createValidationSchema() to handle codebaseIndexEmbedderModelDimension as a required number for OpenAI Compatible provider.
• Testing:
  • Verified save functionality and error display for OpenAI Compatible provider.
  • Ensured other providers (OpenAI, Ollama, Gemini) function correctly.

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