Prepare a release

Input: optional version. Accept 0.9.0, 0.9.0-rc3, 0.9.0rc3, or the corresponding v-prefixed tag. Alpha and beta channels are also supported, including Python spellings 0.9.0a3 and 0.9.0b3. Normalize to:

• pyproject.toml and changelog version: hyphenated (0.9.0-rc3).
• Git tag: v-prefixed and hyphenated (v0.9.0-rc3).
• Distribution filename / normalized PyPI version: PEP 440 (0.9.0rc3).

The Release workflow in .github/workflows/release.yml compares the tag without v to [project].version literally. Do not put the normalized PEP 440 spelling in pyproject.toml for a hyphenated tag. Hatchling normalizes distribution filenames but can preserve the source spelling in package metadata; compare metadata versions using packaging.version.Version, not raw strings.