Consolidate Rust port requirements and remove refactor notes docs

Requirements.md

@@ -11,7 +11,31 @@ It is based on the current `lora-refactor` code state and captures:
 
 Function names below are C++ references. Rust naming/layout may differ, but the behavior must remain equivalent.
 
-## 2. System-Level Requirements
+## 2. Refactored Architecture Baseline
+
+The `lora-refactor` branch split role-specific runtime from the previous large `main.cpp` into dedicated modules while keeping a single firmware image:
+
+- `src/main.cpp` is a thin coordinator that:
+  - detects role and initializes shared platform subsystems,
+  - prepares role module configuration,
+  - calls `begin()` once,
+  - delegates runtime in `loop()`.
+- sender runtime ownership:
+  - `src/sender_state_machine.h`
+  - `src/sender_state_machine.cpp`
+- receiver runtime ownership:
+  - `src/receiver_pipeline.h`
+  - `src/receiver_pipeline.cpp`
+- receiver shared mutable state used by setup wiring and runtime:
+  - `src/app_context.h` (`ReceiverSharedState`)
+
+Sender state machine invariants must remain behavior-equivalent:
+- single inflight batch at a time,
+- ACK acceptance only for matching `batch_id`,
+- retry bounded by `BATCH_MAX_RETRIES`,
+- queue depth bounded by `BATCH_QUEUE_DEPTH`.
+
+## 3. System-Level Requirements
 
 - Role selection:
   - `Sender` when `GPIO14` reads HIGH.
@@ -58,7 +82,7 @@ Function names below are C++ references. Rust naming/layout may differ, but the
   - history day-file resolution prefers local-date filenames and falls back to legacy UTC-date filenames.
   - history parser supports both current (`ts_utc,ts_hms_local,p_w,...`) and legacy (`ts_utc,p_w,...`) layouts.
 
-## 3. Protocol and Data Contracts
+## 4. Protocol and Data Contracts
 
 - `LoraMsgKind`:
   - `BatchUp=0`
@@ -81,8 +105,13 @@ Function names below are C++ references. Rust naming/layout may differ, but the
   - `device.name`: `<device_id>`
   - `device.model`: `DD3-LoRa-Bridge`
   - `device.manufacturer`: `AcidBurns`
+  - drift guards:
+    - canonical value is `HA_MANUFACTURER` in `include/config.h`,
+    - compile-time lock via `static_assert` in `include/config.h`,
+    - script guard `test/check_ha_manufacturer.ps1`,
+    - smoke test guard `test/test_refactor_smoke/test_refactor_smoke.cpp`.
 
-## 4. Module and Function Requirements
+## 5. Module and Function Requirements
 
 ## `src/config.cpp`
 
@@ -335,15 +364,25 @@ Internal route/state functions to preserve behavior:
 - `test_receiver_loop`
   - decode test JSON, update display test markers, publish MQTT test topic.
 
-## `src/main.cpp` (Core Orchestration)
+## `src/app_context.h`
 
-These functions define end-to-end firmware behavior and must have equivalents:
+- `ReceiverSharedState`
+  - retains receiver-owned shared status/fault/discovery state used by setup wiring and runtime.
 
+## `src/sender_state_machine.h/.cpp` (Sender Runtime)
+
+Public API:
+- `SenderStateMachineConfig`
+- `SenderStats`
+- `SenderStateMachine::begin(...)`
+- `SenderStateMachine::loop()`
+- `SenderStateMachine::stats()`
+
+Behavior-critical internals (migrated from pre-refactor `main.cpp`) that must remain equivalent:
 - Logging/utilities:
   - `serial_debug_printf`
   - `bit_count32`
   - `abs_diff_u32`
-
 - Meter-time anchoring and ingest:
   - `meter_time_update_snapshot`
   - `set_last_meter_sample`
@@ -352,13 +391,9 @@ These functions define end-to-end firmware behavior and must have equivalents:
   - `meter_reader_task_entry`
   - `meter_reader_start`
   - `meter_reader_pump`
-
-- Sender/receiver state setup and shared state:
-  - `init_sender_statuses`
+- Sender state/data handling:
   - `update_battery_cache`
   - `battery_sample_due`
-
-- Queue and sample batching:
   - `batch_queue_drop_oldest`
   - `sender_note_rx_reject`
   - `sender_log_diagnostics`
@@ -367,8 +402,7 @@ These functions define end-to-end firmware behavior and must have equivalents:
   - `reset_build_counters`
   - `append_meter_sample`
   - `last_sample_ts`
-
-- Fault tracking/publish:
+- Sender fault handling:
   - `note_fault`
   - `clear_faults`
   - `sender_reset_fault_stats`
@@ -377,11 +411,40 @@ These functions define end-to-end firmware behavior and must have equivalents:
   - `age_seconds`
   - `counters_changed`
   - `publish_faults_if_needed`
+- Sender-specific encoding/scheduling:
+  - `kwh_to_wh_from_float`
+  - `float_to_i16_w`
+  - `float_to_i16_w_clamped`
+  - `battery_mv_from_voltage`
+  - `compute_batch_ack_timeout_ms`
+  - `send_batch_payload`
+  - `invalidate_inflight_encode_cache`
+  - `prepare_inflight_from_queue`
+  - `send_inflight_batch`
+  - `send_meter_batch`
+  - `send_sync_request`
+  - `resend_inflight_batch`
+  - `finish_inflight_batch`
+  - `sender_loop`
 
-- Watchdog:
-  - `watchdog_init`
-  - `watchdog_kick`
+## `src/receiver_pipeline.h/.cpp` (Receiver Runtime)
 
+Public API:
+- `ReceiverPipelineConfig`
+- `ReceiverStats`
+- `ReceiverPipeline::begin(...)`
+- `ReceiverPipeline::loop()`
+- `ReceiverPipeline::stats()`
+
+Behavior-critical internals (migrated from pre-refactor `main.cpp`) that must remain equivalent:
+- Receiver setup/state:
+  - `init_sender_statuses`
+- Fault handling/publish:
+  - `note_fault`
+  - `clear_faults`
+  - `age_seconds`
+  - `counters_changed`
+  - `publish_faults_if_needed`
 - Binary helpers and ID conversion:
   - `write_u16_le`
   - `read_u16_le`
@@ -391,39 +454,27 @@ These functions define end-to-end firmware behavior and must have equivalents:
   - `read_u32_be`
   - `sender_id_from_short_id`
   - `short_id_from_sender_id`
-
-- Numeric normalization/sanitization:
-  - `kwh_to_wh_from_float`
-  - `float_to_i16_w`
-  - `float_to_i16_w_clamped`
-  - `battery_mv_from_voltage`
-
-- Timeout and airtime-driven scheduling:
+- LoRa RX/TX pipeline:
   - `compute_batch_rx_timeout_ms`
-  - `compute_batch_ack_timeout_ms`
-
-- LoRa TX pipeline:
-  - `send_batch_payload`
   - `send_batch_ack`
-  - `invalidate_inflight_encode_cache`
-  - `prepare_inflight_from_queue`
-  - `send_inflight_batch`
-  - `send_meter_batch`
-  - `send_sync_request`
-  - `resend_inflight_batch`
-  - `finish_inflight_batch`
-
-- LoRa RX reassembly/decode:
   - `reset_batch_rx`
   - `process_batch_packet`
-
-- Role loop orchestration:
-  - `setup`
-  - `sender_loop`
   - `receiver_loop`
-  - `loop`
 
-## 5. Rust Porting Constraints and Recommendations
+## `src/main.cpp` (Thin Coordinator)
+
+Current core orchestration requirements:
+- `setup`
+  - initialize shared subsystems once,
+  - instantiate role config and call role `begin`,
+  - keep role-specific runtime out of this file.
+- `loop`
+  - delegate to `SenderStateMachine::loop()` or `ReceiverPipeline::loop()` by role.
+- Watchdog wrapper remains in coordinator:
+  - `watchdog_init`
+  - `watchdog_kick`
+
+## 6. Rust Porting Constraints and Recommendations
 
 - Preserve wire compatibility first:
   - LoRa frame byte layout, CRC16, ACK format, payload schema v3.
@@ -439,14 +490,14 @@ These functions define end-to-end firmware behavior and must have equivalents:
   - `FaultType`, `RxRejectReason`, `LoraMsgKind`.
 
 Suggested Rust module split:
-- `config`, `ids`, `meter`, `power`, `time`, `lora_transport`, `payload_codec`, `batch`, `mqtt`, `wifi_cfg`, `sd_log`, `web`, `display`, `runtime`.
+- `config`, `ids`, `meter`, `power`, `time`, `lora_transport`, `payload_codec`, `sender_state_machine`, `receiver_pipeline`, `app_context`, `mqtt`, `wifi_cfg`, `sd_log`, `web`, `display`, `runtime`.
 
 Suggested Rust primitives:
 - async task for meter reader + bounded channel (drop-oldest behavior).
 - explicit state structs for sender/receiver loops.
 - serde-free/manual codec for wire compatibility where needed.
 
-## 6. Port Validation Checklist
+## 7. Port Validation Checklist
 
 - Sender unsynced boot sends only sync requests.
 - ACK time bootstrap unlocks normal sender sampling.
@@ -459,3 +510,21 @@ Suggested Rust primitives:
 - History endpoint reads current and legacy CSV layouts successfully.
 - History endpoint can read both local-date and legacy UTC-date day filenames.
 - MQTT state/fault payload fields match existing names and semantics.
+
+## 8. Port Readiness Audit (2026-02-20)
+
+Evidence checked on `lora-refactor`:
+- build verification:
+  - `pio run -e lilygo-t3-v1-6-1`
+  - `pio run -e lilygo-t3-v1-6-1-test`
+- drift guard verification:
+  - `powershell -ExecutionPolicy Bypass -File test/check_ha_manufacturer.ps1`
+- refactor ownership verification:
+  - sender state machine state/API present in `src/sender_state_machine.h/.cpp`,
+  - receiver pipeline API present in `src/receiver_pipeline.h/.cpp`,
+  - coordinator remains thin in `src/main.cpp`.
+
+Findings:
+- Requirements are functionally met by current C++ baseline from static/code-build checks.
+- The old requirement ownership under `src/main.cpp` was stale; this document now maps that behavior to `sender_state_machine` and `receiver_pipeline`.
+- No wire/protocol or persistence contract drift found in this audit.