Snake case converter

Write a function `to_snake_case(s: str) -> str` that converts an input string to snake_case. The conversion rules are: 1. Replace all spaces and hyphens (`-`) with underscores (`_`). 2. Insert an underscore between a lowercase/digit and an uppercase letter (e.g., `camelCase` → `camel_Case`). 3. Convert all letters to lowercase. 4. Ensure there are no leading or trailing underscores, and no consecutive underscores (collapse multiple underscores into one). Examples: - `"hello world"` → `"hello_world"` - `"camelCase"` → `"camel_case"` - `"foo-bar_baz"` → `"foo_bar_baz"` - `"Hello World"` → `"hello_world"` - `"getHTTPResponse"` → `"get_http_response"` (see rule 2: insert underscore before an uppercase that follows a lowercase/digit, and also before an uppercase that follows another uppercase? The rule is: an underscore is inserted between a lowercase/digit and an uppercase (`aA` → `a_A`) AND between an uppercase and an uppercase if the previous character is also uppercase? Actually, to handle sequences of uppercase letters correctly, use the common rule: insert underscore before an uppercase if the previous character is lowercase or digit, OR if the previous character is uppercase and the next character is lowercase. This matches converting `getHTTPResponse` to `get_http_response`.)

>>> to_snake_case("hello world")
'hello_world'
>>> to_snake_case("camelCase")
'camel_case'
>>> to_snake_case("foo-bar_baz")
'foo_bar_baz'
>>> to_snake_case("Hello World")
'hello_world'
>>> to_snake_case("getHTTPResponse")
'get_http_response'