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/__init__.py

@@ -1,5 +1,4 @@
 from app.models.base import Base
-from app.models.filament import Filament
 from app.models.job_bracket import JobBracket
 from app.models.job_log import JobLog
 from app.models.pricing import PricingConfig
@@ -10,4 +9,4 @@ from app.models.printer_type import PrinterType
 from app.models.stl_cache import StlCache
 from app.models.todo import Todo
 
-__all__ = ["Base", "Printer", "PrinterLog", "PrinterType", "Filament", "JobBracket", "JobLog", "PrintJob", "StlCache", "Todo", "PricingConfig"]
+__all__ = ["Base", "Printer", "PrinterLog", "PrinterType", "JobBracket", "JobLog", "PrintJob", "StlCache", "Todo", "PricingConfig"]