fix(deps): pin bincode to v2.0 (v3.0 intentionally broken)

[Lenvanderhof]

Summary

• Pin bincode dependency from 3.0 to 2.0

Problem

bincode 3.0.0 was published with an intentional compile_error! pointing to https://xkcd.com/2347/ (the "Dependency" comic about the fragility of software dependencies).

This caused all CI builds to fail with:

error: https://xkcd.com/2347/
 --> /home/runner/.cargo/registry/src/.../bincode-3.0.0/src/lib.rs:1:1
  |
1 | compile_error!("https://xkcd.com/2347/");
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Solution

Pin bincode to version 2.0 which works correctly.

Test plan

• CI passes with this change
• Existing functionality works with bincode 2.0

🤖 Generated with Claude Code

[Lenvanderhof]

Superseded - bincode needs to be 1.3, not 2.0, due to API changes