feat: Add extra weight, price tracking, print history, usage analytics

- Extra Weight Field (#14): Track DryPods, custom holders in spool weight
  calculations. New extra_weight field on spool with DB migration.

- Price/Cost Tracking: Compute remaining_value based on remaining weight
  and price. Added column to spool list, inventory value on dashboard.

- Print History: Show print job history on spool detail page with
  collapsible table showing filename, filament used, status, dates.

- Usage Analytics: New dashboard component with time-series chart
  showing daily consumption, period selector (7/30/90 days), and
  material breakdown. New API endpoints for analytics data.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

spoolman/api/v1/other.py

@@ -1,13 +1,16 @@
 """Filament related endpoints."""
 
 import logging
-from typing import Annotated
+from datetime import datetime, timedelta
+from typing import Annotated, Optional
 
-from fastapi import APIRouter, Depends
+import sqlalchemy
+from fastapi import APIRouter, Depends, Query
 from pydantic import BaseModel, Field, RootModel
+from sqlalchemy import func
 from sqlalchemy.ext.asyncio import AsyncSession
 
-from spoolman.database import filament, spool
+from spoolman.database import filament, models, spool
 from spoolman.database.database import get_db_session
 
 logger = logging.getLogger(__name__)
@@ -173,3 +176,118 @@ async def rename_location(
     logger.info("Renaming location %s to %s", location, body.name)
     await spool.rename_location(db=db, current_name=location, new_name=body.name)
     return body.name
+
+
+class UsageDataPoint(BaseModel):
+    """A single data point for usage analytics."""
+
+    date: str = Field(description="Date in YYYY-MM-DD format.")
+    weight_used: float = Field(description="Total weight used in grams (positive value).")
+
+
+@router.get(
+    "/analytics/usage",
+    name="Get usage analytics",
+    description="Get filament usage data aggregated by day for the specified period.",
+    response_model=list[UsageDataPoint],
+)
+async def get_usage_analytics(
+    *,
+    db: Annotated[AsyncSession, Depends(get_db_session)],
+    days: Annotated[
+        int,
+        Query(description="Number of days to look back.", ge=1, le=365),
+    ] = 30,
+) -> list[UsageDataPoint]:
+    """Get usage analytics aggregated by day."""
+    # Calculate the start date
+    start_date = datetime.utcnow() - timedelta(days=days)
+
+    # Query adjustments grouped by date
+    # Only include negative values (filament used, not added)
+    stmt = (
+        sqlalchemy.select(
+            func.date(models.SpoolAdjustment.timestamp).label("date"),
+            func.sum(
+                sqlalchemy.case(
+                    (models.SpoolAdjustment.value < 0, -models.SpoolAdjustment.value),
+                    else_=0,
+                )
+            ).label("weight_used"),
+        )
+        .where(models.SpoolAdjustment.timestamp >= start_date)
+        .where(models.SpoolAdjustment.adjustment_type == "weight")
+        .group_by(func.date(models.SpoolAdjustment.timestamp))
+        .order_by(func.date(models.SpoolAdjustment.timestamp))
+    )
+
+    result = await db.execute(stmt)
+    rows = result.all()
+
+    # Fill in missing dates with 0
+    data_by_date = {str(row.date): row.weight_used for row in rows}
+    all_dates = []
+    current_date = start_date.date()
+    end_date = datetime.utcnow().date()
+
+    while current_date <= end_date:
+        date_str = current_date.strftime("%Y-%m-%d")
+        all_dates.append(
+            UsageDataPoint(
+                date=date_str,
+                weight_used=data_by_date.get(date_str, 0),
+            )
+        )
+        current_date += timedelta(days=1)
+
+    return all_dates
+
+
+class MaterialUsage(BaseModel):
+    """Usage breakdown by material."""
+
+    material: str = Field(description="Material name.")
+    weight_used: float = Field(description="Total weight used in grams.")
+
+
+@router.get(
+    "/analytics/by-material",
+    name="Get usage by material",
+    description="Get filament usage breakdown by material type.",
+    response_model=list[MaterialUsage],
+)
+async def get_usage_by_material(
+    *,
+    db: Annotated[AsyncSession, Depends(get_db_session)],
+    days: Annotated[
+        Optional[int],
+        Query(description="Number of days to look back. If not set, returns all-time usage.", ge=1, le=365),
+    ] = None,
+) -> list[MaterialUsage]:
+    """Get usage breakdown by material."""
+    # Join adjustments with spools and filaments to get material
+    stmt = (
+        sqlalchemy.select(
+            func.coalesce(models.Filament.material, "Unknown").label("material"),
+            func.sum(
+                sqlalchemy.case(
+                    (models.SpoolAdjustment.value < 0, -models.SpoolAdjustment.value),
+                    else_=0,
+                )
+            ).label("weight_used"),
+        )
+        .join(models.Spool, models.SpoolAdjustment.spool_id == models.Spool.id)
+        .join(models.Filament, models.Spool.filament_id == models.Filament.id)
+        .where(models.SpoolAdjustment.adjustment_type == "weight")
+    )
+
+    if days is not None:
+        start_date = datetime.utcnow() - timedelta(days=days)
+        stmt = stmt.where(models.SpoolAdjustment.timestamp >= start_date)
+
+    stmt = stmt.group_by(models.Filament.material).order_by(func.sum(-models.SpoolAdjustment.value).desc())
+
+    result = await db.execute(stmt)
+    rows = result.all()
+
+    return [MaterialUsage(material=row.material or "Unknown", weight_used=row.weight_used) for row in rows]