Problem

Metadata is typed as List(#(String, String)), which forces every call site to manually convert non-string values:

birch.debug_m("Found test files", [
  #("count", int.to_string(list.length(files))),
])

This is verbose and repetitive, especially for Int, Float, and Bool values that appear frequently in structured logging.

Proposal

Option A — Helper function (minimal, non-breaking):

pub fn meta(key: String, value: a) -> #(String, String) {
  #(key, string.inspect(value))
}

// Usage:
birch.debug("Found files", [birch.meta("count", 42)])

Option B — Sum type for values (richer, breaking):

pub type MetadataValue {
  StringVal(String)
  IntVal(Int)
  FloatVal(Float)
  BoolVal(Bool)
}

pub type Metadata = List(#(String, MetadataValue))

This would let JSON and console handlers format values with proper types rather than everything being a string.

Option C — Both: add the meta helper now (non-breaking), consider the sum type for a future major version.

Context

In real-world usage (ccl_gleam test runner), nearly every metadata value requires an explicit int.to_string or similar conversion, adding noise to every log call.