Explicit readable presentation of structured graphiti fact records.

Public search returns the records themselves. This operation is opt-in; legacy recall calls it before constructing its readable memory block.

Pure Elixir — graphiti runs in Python, but we extract its edges into Elixir maps and format them here, never reaching back into Python for formatting.

Output shape per fact:

- {fact} (created …) (valid from …) (invalid since …) (expired …)

Timestamp normalisation matches the server's pipelines/formatting.py so consumers see identical fact text from either stack.

See test-trees/unit/format-fact_TEST_TREES.md.