WhatsApp can deliver a sender LID instead of a phone number. The channel
already learns the LID->phone mapping at runtime, but only after a message
that carries both values, so the first message from a contact can't be
resolved to a phone number.
Seed the mapping on startup from two sources:
- reverse mapping files the bridge persists in the auth directory
(lid-mapping-<lid>_reverse.json), resolved via get_runtime_subdir so it
respects a custom runtime dir
- a new optional channels.whatsapp.lidMappings config dict for static
mappings (takes precedence over the on-disk files)
Malformed/empty mapping files are ignored rather than failing startup.
Adds tests for both sources, precedence, malformed files and the
no-auth-dir case, plus docs for the new config field.
franciscomaestreandXubin Ren
99e158c062