Allow configuring API connection max retry attempts

Feature Request

Problem

When Claude Code fails to connect to the API (e.g., UND_ERR_SOCKET), it retries up to 10 times by default. This value is hardcoded and cannot be configured.

In some network environments (unstable connections, proxy setups, etc.), 10 retries means a long wait when the API is genuinely unreachable. Users should be able to control this behavior.

Current Behavior

Unable to connect to API (UND_ERR_SOCKET)
Retrying in 0 seconds… (attempt 10/10)

The max retry count (10) is hardcoded with no way to override it.

Proposed Solution

Add a configurable option for API connection max retry attempts. This could be:

• An environment variable, e.g., CLAUDE_API_MAX_RETRIES=4
• A setting in ~/.claude/settings.json, e.g., "apiMaxRetries": 4
• A CLI flag, e.g., claude --max-retries 4

Any of these approaches would work. The key requirement is that users can reduce (or increase) the retry count based on their network conditions.

Use Case

• Users behind corporate proxies or firewalls who know quickly whether the connection will succeed
• Users who prefer fast failure over long retry loops
• CI/CD environments where fast failure is preferred