feat: Add spool adjustment history tracking (#6)

Track history of all spool weight/length adjustments with timestamps and comments:

Backend:
- Add SpoolAdjustment database model with spool_id, timestamp, type, value, comment
- Add Alembic migration for spool_adjustment table
- Add SpoolAdjustment Pydantic model for API responses
- Update use_weight, use_length, and measure functions to record adjustments
- Add GET /api/v1/spool/{id}/adjustments endpoint for history retrieval
- Add optional comment parameter to use/measure endpoints

Frontend:
- Add ISpoolAdjustment interface to spool model
- Add collapsible adjustment history table to spool show page
- Display timestamp, type (weight/length), amount, and comment
- Add translation keys for history table

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

spoolman/api/v1/spool.py

@@ -11,7 +11,7 @@ from fastapi.responses import JSONResponse
 from pydantic import BaseModel, Field, field_validator
 from sqlalchemy.ext.asyncio import AsyncSession
 
-from spoolman.api.v1.models import Message, Spool, SpoolEvent
+from spoolman.api.v1.models import Message, Spool, SpoolAdjustment, SpoolEvent
 from spoolman.database import spool
 from spoolman.database.database import get_db_session
 from spoolman.database.utils import SortOrder
@@ -105,10 +105,22 @@ class SpoolUpdateParameters(SpoolParameters):
 class SpoolUseParameters(BaseModel):
     use_length: Optional[float] = Field(None, description="Length of filament to reduce by, in mm.", examples=[2.2])
     use_weight: Optional[float] = Field(None, description="Filament weight to reduce by, in g.", examples=[5.3])
+    comment: Optional[str] = Field(
+        None,
+        max_length=256,
+        description="Optional comment about this adjustment (e.g., 'printed cover piece').",
+        examples=["Test print"],
+    )
 
 
 class SpoolMeasureParameters(BaseModel):
     weight: float = Field(description="Current gross weight of the spool, in g.", examples=[200])
+    comment: Optional[str] = Field(
+        None,
+        max_length=256,
+        description="Optional comment about this adjustment (e.g., 'weighed after print').",
+        examples=["After printing benchy"],
+    )
 
 
 @router.get(
@@ -513,11 +525,11 @@ async def use(  # noqa: ANN201
         )
 
     if body.use_weight is not None:
-        db_item = await spool.use_weight(db, spool_id, body.use_weight)
+        db_item = await spool.use_weight(db, spool_id, body.use_weight, comment=body.comment)
         return Spool.from_db(db_item)
 
     if body.use_length is not None:
-        db_item = await spool.use_length(db, spool_id, body.use_length)
+        db_item = await spool.use_length(db, spool_id, body.use_length, comment=body.comment)
         return Spool.from_db(db_item)
 
     return JSONResponse(
@@ -543,7 +555,7 @@ async def measure(  # noqa: ANN201
     body: SpoolMeasureParameters,
 ):
     try:
-        db_item = await spool.measure(db, spool_id, body.weight)
+        db_item = await spool.measure(db, spool_id, body.weight, comment=body.comment)
         return Spool.from_db(db_item)
     except SpoolMeasureError as e:
         logger.exception("Failed to update spool measurement.")
@@ -551,3 +563,32 @@ async def measure(  # noqa: ANN201
             status_code=400,
             content={"message": e.args[0]},
         )
+
+
+@router.get(
+    "/{spool_id}/adjustments",
+    name="Get spool adjustment history",
+    description="Get the history of all weight/length adjustments for a spool.",
+    response_model_exclude_none=True,
+    responses={
+        200: {"model": list[SpoolAdjustment]},
+        404: {"model": Message},
+    },
+)
+async def get_adjustments(
+    db: Annotated[AsyncSession, Depends(get_db_session)],
+    spool_id: int,
+    limit: Annotated[
+        Optional[int],
+        Query(title="Limit", description="Maximum number of items in the response."),
+    ] = None,
+    offset: Annotated[int, Query(title="Offset", description="Offset in the full result set if a limit is set.")] = 0,
+) -> JSONResponse:
+    db_items, total_count = await spool.get_adjustments(db, spool_id, limit=limit, offset=offset)
+    return JSONResponse(
+        content=jsonable_encoder(
+            [SpoolAdjustment.from_db(db_item) for db_item in db_items],
+            exclude_none=True,
+        ),
+        headers={"x-total-count": str(total_count)},
+    )