@spec doc_string_contents(Metastatic.AST.meta_ast()) :: MapSet.t(String.t())

Collects string content from documentation attributes (@moduledoc, @doc, @typedoc).

Returns a MapSet of strings that appear as values of documentation module attributes. Checks can use this to skip doc strings during literal analysis, preventing false positives when documentation merely mentions patterns like Phoenix.HTML.raw/1 or URL examples.

@spec module_attribute?(String.t()) :: boolean()

Returns true if a variable name represents a module attribute (starts with @), which should be excluded from snake_case checks since module attribute names follow their own conventions.

@spec module_name?(String.t()) :: boolean()

Returns true if the string looks like a module name (PascalCase or contains dots like Enum.map), not a regular variable.

@spec safe_stdlib_call?(String.t()) :: boolean()

Returns true if the function name belongs to a well-known standard library module that should never be flagged as user-facing I/O, HTTP, auth, file operations, etc.

This prevents false positives like Keyword.get being flagged as an HTTP "get" call, or Map.fetch! being flagged as a database "fetch".

@spec special_variable?(String.t()) :: boolean()

Returns true if a variable name is a well-known Elixir special form or compiler artifact that should be excluded from naming checks.