fix(core): sync Cargo.toml version to 0.2.0

The npm publish workflow failed because Cargo.toml was still at
0.1.0 while package.json files were at 0.2.0. The napi artifacts
command uses the Cargo version, causing it to try publishing an
already-existing version.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: fricoben

packages/core/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "vibetracking-core"
-version = "0.1.0"
+version = "0.2.0"
 edition = "2021"
 license = "MIT"
 description = "Native Rust core for vibetracking CLI - high-performance session parsing"