fix(deps): pin bincode to v1.3 for API compatibility (#13)

## Summary

- Pin `bincode` to 1.3.3 (latest 1.x) for API compatibility
- bincode 2.0+ uses completely new `Encode`/`Decode` trait API
- Current code uses legacy `serialize()`/`deserialize()` functions
- Remove `Cargo.lock` from `.gitignore` for reproducible CI with
`--locked` flag

## Test Plan

- [ ] CI passes on all platforms
- [ ] Build with `--locked` succeeds
- [ ] All serialization tests pass

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

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Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
Co-authored-by: Len P. van der Hof <Lenvanderhof@ReasonKit.sh>

ReasonKit Mem v0.1.4

chore(release): bump versions to 0.1.2

Publishing new versions to crates.io with latest fixes.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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