add Shadowsocks (ss://) support

[Hoot-Code]

Add Shadowsocks (ss://) support

Summary

This PR adds full Shadowsocks configuration support alongside the existing VLESS and Trojan protocols. Users can now paste a ss:// share URL into the config input and have it scanned and validated like any other protocol.

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Changes

internal/xraytest/parser.go

• Added Method string field to VLESSConfig (holds the cipher, e.g. aes-256-gcm, chacha20-ietf-poly1305)
• Extended ParseProxyURL to dispatch ss:// URLs to the new parser
• Added ParseShadowsocks() supporting both URL formats:
  • SIP002 (modern): ss://BASE64(method:password)@host:port#remark
  • Legacy: ss://BASE64(method:password@host:port)#remark
• Added ToShadowsocksURL() to reconstruct a SIP002 share URL from a parsed config
• Added ssDecodeUserinfo() and base64DecodeSS() helpers that tolerate missing padding and both standard/URL-safe base64 alphabets

internal/xraytest/builder.go

• Updated buildOutbound() to dispatch on Protocol == "shadowsocks"
• Added buildShadowsocksOutbound() which generates a valid Xray shadowsocks outbound block with method and password

internal/ui/model.go

• Updated config input placeholder to include ss://

internal/xraytest/parser_test.go

• Added 5 new tests: SIP002 parsing, legacy parsing, dispatch via ParseProxyURL, round-trip via ToShadowsocksURL, and invalid port rejection

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Supported ciphers

Any cipher string is accepted (the value is passed through to Xray). Common ones include:
aes-128-gcm · aes-256-gcm · chacha20-ietf-poly1305 · xchacha20-ietf-poly1305 · 2022-blake3-aes-256-gcm

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Testing

go test ./internal/xraytest/...

All existing tests continue to pass. New tests cover both URL formats, the dispatch layer, round-trip URL generation, and error handling.