docs: align rust-port requirements with current helper ownership

- Update lora transport helper ownership to reference lora_frame_logic (lora_build_frame, lora_parse_frame, lora_crc16_ccitt).
- Remove sender fault-helper entries (ge_seconds, counters_changed, publish_faults_if_needed) that are implemented receiver-side.

Requirements.md

@@ -216,7 +216,7 @@ Sender state machine invariants must remain behavior-equivalent:
   - compute packet airtime from SF/BW/CR/preamble.
 - Internal behavior-critical helpers:
   - `note_reject`
-  - `crc16_ccitt`
+  - `lora_build_frame`, `lora_parse_frame`, `lora_crc16_ccitt` (implemented in `lib/dd3_transport_logic/src/lora_frame_logic.cpp`)
 
 ## `lib/dd3_legacy_core/src/payload_codec.cpp`
 
@@ -408,9 +408,6 @@ Behavior-critical internals (migrated from pre-refactor `main.cpp`) that must re
   - `sender_reset_fault_stats`
   - `sender_reset_fault_stats_on_first_sync`
   - `sender_reset_fault_stats_on_hour_boundary`
-  - `age_seconds`
-  - `counters_changed`
-  - `publish_faults_if_needed`
 - Sender-specific encoding/scheduling:
   - `kwh_to_wh_from_float`
   - `float_to_i16_w`