auto symlink ~/.tea/local/bin/foo on installs

[mxcl]

it’s always symlinked to v* so it can only be the latest version. This suits what most people want this feature for.

Refs #600

[what-the-diff]

PR Summary

• Moved install function to a new location
  The install function has been relocated to prefab/install.ts for better organization.
• Added link() helper for symlinking
  A new link() helper has been added to create symlinks for each package installed, ensuring they're accessible in local/bin.
• Renamed and moved usePackageYAML function
  The usePackageYAML function has been renamed to useYAMLFrontMatter and now resides in the hooks section of the codebase.
• Modified getVerbosity & getColor for CI compatibility
  Both functions have been updated to be compatible with non-TTY environments, such as when CI=1 or --json is set.
• Renamed useExec.ts to setup.ts
  The file useExec.ts has been renamed to setup.ts for better naming consistency.
• Removed unused imports and variables in setup
  Unnecessary imports and variables have been removed from the setup file, streamlining the code.
• Added a test for tea commands in dev environments
  A new test has been implemented to ensure that tea commands work properly within development environments created by the run() function.

[coveralls]

coverage: 48.386% (-32.0%) from 80.398% when pulling a0e5732 on auto-symlink into 6481085 on main.

[coveralls]

Changes unknown
when pulling a0e5732 on auto-symlink
into ** on main**.

[coveralls]

Changes unknown
when pulling a0e5732 on auto-symlink
into ** on main**.