Bump version to 6.1 (20260827)

[madeye]

Marketing version 6.1, Release build number 20260827 (Debug untouched at 105).

Ships everything merged since 6.0 build 20260812:

• Send the controller secret when TrafficStore polls /connections (Send the controller secret when TrafficStore polls /connections #109)
• Inject the PROXY fallback group only when something references it (Inject the PROXY fallback group only when something references it #108)
• Hermetic SOCKS5 proxy test target (Give the SOCKS5 proxy test a hermetic target #107)
• meow-rs 0.21.1, sing-mux enabled, repo move to meow-rs/meow-rs (Bump meow-rs kernel to 0.21.1, enable sing-mux, and move to meow-rs/meow-rs #106)
• Proxy-group selections scoped per subscription; selectedNode retired (Scope proxy-group selections per subscription and retire selectedNode #105)
• mihomo User-Agent for subscription fetches (Use mihomo's User-Agent when fetching subscriptions #104)
• boring-tls enabled so client-fingerprint spoofs the Client Hello (Enable boring-tls so client-fingerprint actually spoofs the Client Hello #102)
• Proxy node hostnames resolved via configured DNS (Resolve proxy node hostnames with the configured DNS #101)
• GeoLite2-ASN.mmdb provisioning for IP-ASN rules (Provision GeoLite2-ASN.mmdb for IP-ASN rules #100)
• NE TCP relay leak fix (Fix NE TCP relay leak that pinned closed flows forever #99)
• Subscription DNS blocks respected (Respect subscription DNS blocks instead of replacing them #98)

Verified locally: swiftlint lint --strict clean, 220 unit tests pass, MAS PKG built and altool validation succeeded.

https://claude.ai/code/session_01RE96utCvf8jMzGGFNyFJsq