Add a per-command `timeout` option that terminates a command once it
exceeds the given duration, preventing commands from hanging indefinitely
in a pipeline. Uses Go duration syntax (e.g. 30s, 5m, 1h30m) and applies
to both shell commands and task calls.
Closes#1569
* refactor: moved/simplified snippets into its own file with tests
* refactor: move snippet to taskfile package
* feat: support snippets with line/col = 0
* feat: functional options for snippets
* feat: added option to hide snippet indicators
* feat: store raw lines for length calculations
* feat: add debug function for TaskfileDecodeError
* fix: decode errors from commands
* fix: schema for defer cmd calls
* fix: linting issues
* refactor: split var and vars into different files like other structures
