Virtualize broker TCP ports

[Weidong Cui (wdcui)]

This PR gives each broker session an independent guest TCP port namespace, keeps Linux backend endpoints private, translates session-local TCP connections and accepted peer addresses, and adds explicit host-to-guest TCP port mappings with reserved endpoint, descriptor replacement, option preservation, and teardown handling.

[github-actions]

🤖 SemverChecks 🤖 ⚠️ Potential breaking API changes detected ⚠️

Click for details

--- failure struct_pub_field_missing: pub struct's pub field removed or renamed ---

Description:
A publicly-visible struct has at least one public field that is no longer available under its prior name. It may have been renamed or removed entirely.
        ref: https://doc.rust-lang.org/cargo/reference/semver.html#item-remove
       impl: https://github.com/obi1kenobi/cargo-semver-checks/tree/v0.50.0/src/lints/struct_pub_field_missing.ron

Failed in:
  field local_address of struct AcceptedPlatformSocket, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-ulitebox/7a63b6de36d1f08d757b72103b15801cf997c8a2/litebox_broker_core/src/socket.rs:31

--- failure trait_method_parameter_count_changed: pub trait method parameter count changed ---

Description:
A trait method now takes a different number of parameters.
        ref: https://doc.rust-lang.org/cargo/reference/semver.html#trait-item-signature
       impl: https://github.com/obi1kenobi/cargo-semver-checks/tree/v0.50.0/src/lints/trait_method_parameter_count_changed.ron

Failed in:
  PlatformSocket::bind now takes 2 instead of 1 parameters, in file /home/runner/work/litebox/litebox/litebox_broker_core/src/socket.rs:224

--- failure method_parameter_count_changed: pub method parameter count changed ---

Description:
A publicly-visible method now takes a different number of parameters, not counting the receiver (self) parameter.
        ref: https://doc.rust-lang.org/cargo/reference/semver.html#fn-change-arity
       impl: https://github.com/obi1kenobi/cargo-semver-checks/tree/v0.50.0/src/lints/method_parameter_count_changed.ron

Failed in:
  litebox_broker_platform_linux_userland::LinuxSocketProvider::new takes 1 parameters in /home/runner/work/litebox/litebox/target/semver-checks/git-ulitebox/7a63b6de36d1f08d757b72103b15801cf997c8a2/litebox_broker_platform_linux_userland/src/socket.rs:58, but now takes 2 parameters in /home/runner/work/litebox/litebox/litebox_broker_platform_linux_userland/src/socket.rs:84