refactor: comprehensive simplification and functional programming improvements
- help_live/index.ex: 2,642→173 lines, 15 section modules + sidebar extracted
MikroTik now real section, dead if false removed
- agent_channel.ex: 2,506→1,751 lines, 3 helper modules extracted
(heartbeat/subscriptions/job_builder), decode_and_process/4 eliminates
8 repeated handle_in patterns, guard-based size checks
- antenna_catalog.ex: 1,174→47 lines, 107 specs → priv/antennas/catalog.json
- topology.ex: unbounded query → batched loading (100/batch),
all guard errors fixed, zero if/case/cond conditionals
- proto: decoder_macros.ex + field_specs.ex infrastructure for
macro-generated protobuf decoders
9d4a5f6d81