Skip favicon fetch from DuckDuckGo for localhost URLs

[bnema]

Problem

When navigating to localhost URLs, the browser unnecessarily attempts to fetch favicons from DuckDuckGo's favicon API:

DBG fetching favicon from DuckDuckGo url=https://icons.duckduckgo.com/ip3/localhost%3A5173.ico

This is wasteful since:

1. DuckDuckGo cannot return a favicon for localhost
2. It adds unnecessary network latency
3. It may cause timeout delays

Proposed Solution

Add a check in internal/infrastructure/favicon/fetcher.go at the start of the Fetch() function to skip fetching for local domains:

• localhost
• 127.0.0.1
• ::1
• Optionally: *.local, 192.168.*, 10.*, 172.16-31.* (private IP ranges)

Implementation Hint

func isLocalDomain(domain string) bool {
    // Check for localhost variants and private IPs
    // Return true to skip external fetch
}

Add the check around line 39-41 in fetcher.go, before the DuckDuckGo request is made.

Files to Modify

• internal/infrastructure/favicon/fetcher.go

Acceptance Criteria

• No DuckDuckGo fetch attempt for localhost URLs
• No DuckDuckGo fetch attempt for 127.0.0.1 URLs
• No DuckDuckGo fetch attempt for ::1 URLs
• Existing favicon fetching for public domains still works