Bump version to 0.3.0

[fracapuano]

Summary

Bumps orca_core from 0.2.1 → 0.3.0 in preparation for the v0.3.0 release.

Also expands the authors list in pyproject.toml to credit additional maintainers who contributed to this release cycle (hand refactor, v2 hands, tactile sensing).

v0.3.0 highlights

• Hand API refactor — split OrcaHand into BaseHand / HardwareHand, typed joint positions, decoupled config from calibration state, mock motor client for hardware-free tests.
• v2 hands — versioned model resolution (v1/v2, left/right) and v2 calibration references.
• Tactile sensing — TactileClient, OrcaHandTouch subclass, orcahand-touch config under v2/, mock client and protocol tests.
• Feetech driver support — auto-detection of motor type and baudrate at connect time, persisted to config.yaml.
• Tensioning & calibration — motors move by default, stall detection, gradual torque release; per-joint/finger calibration CLI.
• uv workflow — migrated dependency management from Poetry to uv.

Note
After this PR is merged, a v0.3.0 tag will be pushed against the merge commit. That tag triggers the existing .github/workflows/release.yml workflow, which publishes the package to PyPI.

A matching GitHub release with full notes will be created at the same time.