chore(release): prepare 0.1.0-rc.2

[zsumz]

Release

Prepare kafka-wire 0.1.0-rc.2 without changing the wire surface.

Changes

• advance all workspace package identities and internal constraints to 0.1.0-rc.2
• refresh both lockfiles and the executable release contract
• regenerate the checked tree with the rc.2 generator identity
• close the post-rc.1 changelog section and mark rc.2 as current in the README

Verification

• complete repository gate across generation, architecture, 1,392 byte vectors, 18 RecordBatches, formatting, Clippy, tests, and rustdoc
• extracted-package qualification for all three public rc.2 archives
• locked fuzz metadata, deterministic seed verification, all five fuzz builds, and 256-run smoke campaigns
• cargo-deny policy
• 669 public API compatibility checks against signed v0.1.0-rc.1
• actionlint and ShellCheck
• signed zsumz release commit

No tag, crates.io package, or GitHub release is created until this exact commit passes every protected hosted check.