Remove internal filament management, integrate FilamentDB, add job detail page

Filament removal:
- Deleted app/models/filament.py, routers/filaments.py, templates/filaments.html
- Migration 0009: drops filaments table and filament_id FK from print_jobs
- Removed Filaments from sidebar and all internal references

FilamentDB integration (read-only):
- app/filamentdb.py: GET /reports/stock with 5-min in-memory cache
- available_materials() / available_colors() populate job form dropdowns
- Falls back to static constants if FilamentDB unreachable
- Dashboard filament count now from FilamentDB rolls_in_stock
- FILAMENTDB_URL added to .env.install; httpx added to requirements

Job detail page (/jobs/{id}):
- Two cards: Job info (customer, material, printer, bracket, timing, cost)
  and File & Geometry (bounding box + volume from stl_cache)
- Log timeline with Add Entry modal
- Filename in jobs list links to detail page

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/models/print_job.py

@@ -3,7 +3,7 @@ import uuid as _uuid
 from datetime import datetime
 from decimal import Decimal
 
-from sqlalchemy import DateTime, Enum, ForeignKey, Integer, Numeric, String, Text, func
+from sqlalchemy import DateTime, Enum, ForeignKey, Integer, String, Text, func
 from sqlalchemy.orm import Mapped, mapped_column, relationship
 
 from app.models.base import Base
@@ -23,7 +23,6 @@ class PrintJob(Base):
     id: Mapped[int] = mapped_column(primary_key=True)
     job_uuid: Mapped[str | None] = mapped_column(String(36), unique=True, default=lambda: str(_uuid.uuid4()))
     printer_id: Mapped[int | None] = mapped_column(ForeignKey("printers.id"))
-    filament_id: Mapped[int | None] = mapped_column(ForeignKey("filaments.id"))
     bracket_id: Mapped[int | None] = mapped_column(ForeignKey("job_brackets.id"))
     name: Mapped[str] = mapped_column(String(200))
     customer: Mapped[str | None] = mapped_column(String(200))
@@ -44,7 +43,6 @@ class PrintJob(Base):
     )
 
     printer: Mapped["Printer"] = relationship(back_populates="jobs")
-    filament: Mapped["Filament | None"] = relationship(back_populates="jobs")
     bracket: Mapped["JobBracket | None"] = relationship(back_populates="jobs")
     logs: Mapped[list["JobLog"]] = relationship(
         back_populates="job", order_by="JobLog.created_at.desc()"