feat: per-unit daemon log trail — rebalance summaries, skip reasons, order/fill lines

CHANGELOG.md

@@ -15,6 +15,16 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   (`application/log_setup.py`); tick errors now log their traceback
   (previously invisible — no handler existed). Interactive CLI output
   unchanged. (#226)
+- **Per-unit daemon log trail** — every evaluated rebalance logs one
+  grep-stable summary (`unit=… rebalance asof=… legs/submitted/round_up/
+  skipped/on_target`, counters partitioning the universe); round-up/skip leg
+  decisions log their full `LegDecision.reason` (the exact Decimals and the
+  binding venue minimum) at INFO; order submits (cid, side, qty, px,
+  venue id) at INFO and refusals at WARN; each applied fill logs
+  cid/qty/price/fee/fee-asset (`OrderFillSync.unit_name`, additive); unit
+  start/stop/step-error transitions logged. Anti-spam pinned: an idle tick
+  (no new bar) adds zero per-unit lines — a unit's inactivity is now
+  explained by the log. (#227)
 
 ### Changed
 

doc/dev/03-decisions.md

@@ -6,6 +6,24 @@ rejected approaches as tombstones.
 
 ---
 
+### 2026-07-14 Unit event trail: runner-attributed lines, bus and log are two sinks (PR #227)  [accepted]
+- **Choice**: order-lifecycle log lines live in the **runner** (per-unit, sees
+  the router's outcome and the unit name) — not the shared router; the new
+  module-logger INFO/WARN lines are emitted **alongside** the existing
+  EventBus `LogEvent`s, not instead (the bus feeds the SSE dashboard, the
+  logger feeds `daemon.log` — two sinks, two audiences). `OrderFillSync`
+  gains an additive `unit_name` for fill attribution; supervisor step errors
+  are logged with traceback then **re-raised** (attribution without
+  swallowing the CLI tick's safety net).
+- **Why**: threading unit identity through the shared router would touch its
+  signature for a logging concern; the runner already owns the name and the
+  outcome. Replacing the bus emits would have silently unplugged the
+  dashboard's live log feed.
+- **Rejected alternatives**: per-unit `LoggerAdapter` injected into the
+  router (signature churn); replacing `LogEvent`s with logging (breaks SSE);
+  logging every idle tick per unit (2 units × 1440 min/day of noise — the
+  anti-spam rule is pinned in the plan).
+
 ### 2026-07-14 Daemon logging spine: root handlers, offset timestamps (PR #226)  [accepted]
 - **Choice**: the daemon's logging config lives in `application/log_setup.py`
   and wires the **root** logger with two owned, tagged handlers (midnight

doc/dev/06-status.md

@@ -183,10 +183,12 @@ engine code: **real-key live enablement** (validate Kraken private endpoints +
 venue-level idempotency against a real-key sandbox, then flip `live_enabled`) — the one
 maintainer step in [`07-roadmap.md`](07-roadmap.md).
 
-- **`daemon-logging` in flight (1/3)**: the logging spine landed (rotated,
+- **`daemon-logging` in flight (2/3)**: the logging spine (rotated,
   tz-offset-timestamped `logs/daemon.log`, manifest `logging:` section, tick
-  tracebacks). Next: the per-unit event trail (leaf 02), tick-timing metrics
-  (leaf 03). Plan: `plans/daemon-logging/`.
+  tracebacks) and the per-unit event trail (rebalance summaries, skip
+  reasons, order/fill lines — a unit's inactivity is now explained by the
+  log) have landed. Next: tick-timing metrics (leaf 03). Plan:
+  `plans/daemon-logging/`.
 
 ## Known gaps / deferred
 

doc/dev/plans/daemon-logging/00-plan.md

@@ -54,7 +54,7 @@ What the audit measured (the evidence this epic answers):
 ## Leaf checklist
 
 - [x] 01 log-setup — `feat/daemon-log-setup` — medium
-- [ ] 02 unit-event-trail — `feat/daemon-unit-event-logs` — medium
+- [x] 02 unit-event-trail — `feat/daemon-unit-event-logs` — medium
 - [ ] 03 tick-timing-metrics — `feat/tick-timing-metrics` — medium
 
 ## Dependencies

trading_bot/application/order_fill_sync.py

@@ -123,6 +123,13 @@ class OrderFillSync:
         :class:`~trading_bot.domain.order.Order` aggregates to update.
     bus : EventBus
         The shared bus to listen on and re-emit updated orders onto.
+    unit_name : str or None, optional
+        The managed unit this sync belongs to, threaded from
+        :func:`~trading_bot.application.service_factory.build_engine` for a
+        single-unit slice. When given, every applied-fill INFO line is prefixed
+        ``unit=<name> ``; when ``None`` (the whole-system / multi-unit path, the
+        default — keeps the historic signature working) the same line is logged
+        without the prefix (starting at ``fill cid=…``).
 
     Examples
     --------
@@ -136,9 +143,12 @@ class OrderFillSync:
 
     """
 
-    def __init__(self, router: OrderRouter, bus: EventBus) -> None:
+    def __init__(
+        self, router: OrderRouter, bus: EventBus, *, unit_name: str | None = None
+    ) -> None:
         self._router = router
         self._bus = bus
+        self._unit_name = unit_name
         # Fill-id dedup: every fill this component has consumed — applied, or
         # deliberately skipped (untracked/terminal on replay) — so a re-emitted
         # event or a replayed history never double-applies. Fills are the PnL
@@ -302,4 +312,21 @@ def _apply(self, order: Order, fill: Fill) -> bool:
                 exc,
             )
             return False
+        # One INFO per applied fill — the execution the log's fill line reports
+        # (signed qty, price, fee) is exactly what reached the tracked order, so a
+        # reader can tie the daemon log to the store's fills table. The fee is
+        # denominated in ``fee_asset`` when the venue set one, else the quote
+        # currency. Prefixed ``unit=<name> `` when this sync knows its unit; the
+        # same line without the prefix otherwise (see the ``unit_name`` param).
+        fee_ccy = fill.fee_asset or fill.instrument.symbol.quote
+        prefix = f"unit={self._unit_name} " if self._unit_name is not None else ""
+        logger.info(
+            "%sfill cid=%s %s @ %s fee=%s %s",
+            prefix,
+            fill.client_order_id,
+            fill.signed_qty,
+            fill.price,
+            fill.fee,
+            fee_ccy,
+        )
         return True