release: prepare v0.6.0

[eareimu]

Release prep

• Finalizes the v0.6.0 release branch after upstream registry propagation.
• Replaces provisional git dependency edges with crates.io dependencies:
  • h3x v0.4.0
  • dhttp v0.2.0
  • dshell v0.4.0
• Regenerates Cargo.lock so the DHTTP, DShell, DDNS, and h3x release-wave crates resolve from crates.io.
• Leaves xtask/release.toml unchanged: pishoo-common remains at 0.5.0-1 with the existing required common-package version.

Release gates

• Upstream registry visibility confirmed for dhttp-identity, dhttp-home, dhttp-access, dhttp, h3x, dyns, and dshell release-wave versions.
• Gateway release surface is S3/R2 product packages only: pishoo DEB, RPM, and Homebrew artifacts.
• Planned release tag: v0.6.0.
• Merge, tag, S3/R2 product publication, and authenticated GitHub Release remain blocked on final PR release CI and explicit user approval.

Verification

• cargo metadata --locked --format-version 1
• cargo +nightly fmt --all -- --check
• git diff --check
• cargo clippy --all-targets --all-features -- -D warnings
• cargo test --all-targets --all-features
• rg -n 'git =|git\\+https://github.com/genmeta|path = "/home/yiyue|patch\\.' Cargo.toml Cargo.lock .cargo/config.toml gateway/Cargo.toml pishoo/Cargo.toml xtask/Cargo.toml