refactor: move SyncDependencies to operations, fix hooks and code quality

[indaco]

Description

Architecture and code quality improvements:

• Move SyncDependencies and DeriveDependencyName from commands/depsync to internal/operations to break circular dependency between command packages
• Create fresh hook runner per RunPreReleaseHooks call instead of using a package-level default, ensuring the current hook list is always used
• Remove blank line between doc comment and CommitParser interface declaration
• Replace fmt.Errorf with typed apperrors.InvalidBumpTypeError in BumpByLabel

The commands/depsync package is kept as a thin delegation wrapper for backward compatibility.

Related Issue

• None

Notes for Reviewers

The commands/depsync package now only delegates to operations.SyncDependencies. Existing callers outside the bump command continue to work unchanged.