fix(metrics): time-series rows get time-ordered ids, so an insert stops costing a disk read (#5149)

Measured on dev (385a579), agent posts cut to five samples still dropped:
flush=8.8s for 990 rows, 6.6s for 680, 8.4s for 1000 — about 110 rows/s,
~9 ms a row, with rules and evaluation near zero. One random read per
row fits a random uuid4 primary key whose index no longer fits in memory:
every new row lands on a random page of it. (Inferred from the rate; the
table and index sizes have not been read.)

- steward.core.ids.time_ordered_id: a UUIDv7-layout string (48-bit ms
  timestamp, then random), same 36-char shape as the stored uuid4 ids, so
  no migration. Python's uuid7() arrives in 3.14; the image runs 3.13.
- Used for plugin_metrics and its hourly rollup, monitor_results,
  audit_events, the docker metrics/hourly/events/logs tables, and the
  traefik and unifi time series.
- MAX_SAMPLES_PER_INGEST 5 → 2 (~400 rows) for now: it fits the agent's
  10 s even at the old rate, so hosts land data whichever way the new rate
  comes out. Raise it once the new rate is measured.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

plugins/traefik/models.py

@@ -1,16 +1,16 @@
 # plugins/traefik/models.py
 from __future__ import annotations
-import uuid
 from datetime import datetime, timezone
 from sqlalchemy import DateTime, Float, Integer, String, Text
 from sqlalchemy.orm import Mapped, mapped_column
 from steward.models.base import Base
+from steward.core.ids import time_ordered_id
 
 
 class TraefikMetric(Base):
     __tablename__ = "traefik_metrics"
 
-    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=lambda: str(uuid.uuid4()))
+    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=time_ordered_id)
     router_name: Mapped[str] = mapped_column(String(255), nullable=False)
     scraped_at: Mapped[datetime] = mapped_column(
         DateTime(timezone=True), nullable=False, default=lambda: datetime.now(timezone.utc)
@@ -41,7 +41,7 @@ class TraefikAccessSummary(Base):
     """Aggregated traffic-origin summary — one row per scheduler tick."""
     __tablename__ = "traefik_access_summaries"
 
-    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=lambda: str(uuid.uuid4()))
+    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=time_ordered_id)
     period_start: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False)
     period_end: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False)
     total_requests: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
@@ -57,7 +57,7 @@ class TraefikGlobalStat(Base):
     """One row per scrape — process-level and config stats."""
     __tablename__ = "traefik_global_stats"
 
-    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=lambda: str(uuid.uuid4()))
+    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=time_ordered_id)
     scraped_at: Mapped[datetime] = mapped_column(
         DateTime(timezone=True), nullable=False, default=lambda: datetime.now(timezone.utc)
     )