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/templates/jobs.html

@@ -46,7 +46,7 @@
         {{ j.job_uuid[:8] if j.job_uuid else '—' }}
       </td>
       <td class="text-white">{{ j.customer or '—' }}</td>
-      <td class="text-secondary">{{ j.file_name or '—' }}</td>
+      <td><a href="/jobs/{{ j.id }}" class="text-secondary text-decoration-none">{{ j.file_name or j.name or '—' }}</a></td>
       <td class="text-secondary">{{ j.printer.name if j.printer else '—' }}</td>
       <td class="text-secondary">
         {% if j.job_material %}{{ j.job_material }}{% if j.job_color %} · {{ j.job_color }}{% endif %}{% else %}—{% endif %}