Add MOT/insurance renewal hints, table service card, and favicon

- Renewal tracking: compute due/overdue status from the most recent
  mot/insurance event (renewal_months, renewal_due_soon_days settings),
  surfaced on the service card and dashboard.
- Service-status card metrics now render as a two-column label/value
  table with row separators instead of wrapping auto-fill grid cells.
- Add a bicycle favicon (favicon.svg) to base + login templates.

Co-Authored-By: opencode <opencode@users.noreply.github.com>

app/services.py

@@ -1,12 +1,68 @@
 from __future__ import annotations
 
 import sqlite3
+from calendar import monthrange
 from dataclasses import dataclass
+from datetime import date
 
 from . import db
 from .config import get_settings
 
 
+@dataclass
+class RenewalDue:
+    """MOT / insurance renewal snapshot for one bike.
+
+    renewal_date: the date the logged MOT/insurance took effect.
+    due_date:     when it falls due (renewal_date + renewal_months).
+    days_until:   due_date - today (negative when overdue).
+    status:
+      "no-data"  -> no MOT/insurance event logged
+      "ok"       -> more than the lead time from due
+      "due-soon" -> within the lead time of the due date
+      "overdue"  -> past the due date
+    """
+
+    renewal_date: date | None
+    due_date: date | None
+    days_until: int | None
+    status: str
+
+
+def _add_months(d: date, months: int) -> date:
+    """Clamp the day to the last valid day of the target month (e.g. Feb 29)."""
+    total = d.month - 1 + months
+    year = d.year + total // 12
+    month = total % 12 + 1
+    day = min(d.day, monthrange(year, month)[1])
+    return date(year, month, day)
+
+
+def compute_renewal_due(
+    conn: sqlite3.Connection, bike: db.Bike, type: str, today: date | None = None
+) -> RenewalDue:
+    """Compute when the most recent `type` (mot/insurance) event falls due."""
+    if today is None:
+        today = date.today()
+    settings = get_settings()
+
+    last = db.latest_event_of_type(conn, bike.id, type)
+    if last is None:
+        return RenewalDue(None, None, None, "no-data")
+
+    renewal_date = last.event_date
+    due_date = _add_months(renewal_date, settings.renewal_months)
+    days_until = (due_date - today).days
+    if days_until < 0:
+        status = "overdue"
+    elif days_until <= settings.renewal_due_soon_days:
+        status = "due-soon"
+    else:
+        status = "ok"
+
+    return RenewalDue(renewal_date, due_date, days_until, status)
+
+
 @dataclass
 class ServiceDue:
     """Service-due snapshot for one bike.
@@ -65,6 +121,8 @@ def compute_service_due(conn: sqlite3.Connection, bike: db.Bike) -> ServiceDue:
 class BikeSummary:
     bike: db.Bike
     due: ServiceDue
+    mot: RenewalDue
+    insurance: RenewalDue
     event_count: int
     total_cost: int
 
@@ -73,6 +131,8 @@ def summarize_bike(conn: sqlite3.Connection, bike: db.Bike) -> BikeSummary:
     return BikeSummary(
         bike=bike,
         due=compute_service_due(conn, bike),
+        mot=compute_renewal_due(conn, bike, "mot"),
+        insurance=compute_renewal_due(conn, bike, "insurance"),
         event_count=db.count_events(conn, bike.id),
         total_cost=db.sum_cost(conn, bike.id),
     )
@@ -113,3 +173,22 @@ def status_text(due: ServiceDue) -> str:
     if due.status == "ok":
         return f"due in {due.miles_until_due:,} mi"
     return f"overdue by {abs(due.miles_until_due):,} mi"
+
+
+def renewal_class(r: RenewalDue) -> str:
+    return {
+        "overdue": "badge-overdue",
+        "due-soon": "badge-due-soon",
+        "ok": "badge-ok",
+        "no-data": "badge-muted",
+    }[r.status]
+
+
+def renewal_text(r: RenewalDue) -> str:
+    if r.status == "no-data":
+        return "not logged"
+    if r.status == "overdue":
+        return f"overdue by {abs(r.days_until)} days"
+    if r.status == "due-soon":
+        return f"due in {r.days_until} days"
+    return f"due in {r.days_until} days"