i18n(de): add German translations for 131 untranslated v2.7 UI strings

Previously untranslated strings added, covering:

Texture import workflow (new in v2.7):
- Multi-Color, Color Count, Smooth Level, Filament Mapping, New Filaments
- Skip Matching, Add Material, Import Model, Processing
- Computing/Applying texture colors, Texture Import Warning
- Auto-merge same filament, Reminder: parameters changed, etc.

Device status / calibration messages:
- Paused (filament ran out), Heating nozzle, Pause (nozzle clog/clumping)
- Pause (step loss/cutter error/front cover/Gcode/AMS offline)
- Pause (nozzle/heatbed temperature malfunction, chamber control problem)
- Calibrating flow ratio, dynamic flow, BirdsEye Camera
- Waiting for heatbed, Updating 3D view, Placing model on bed

Settings and descriptions:
- Purge Mode Fast/Standard, Flush multiplier, Override overhang speed
- Printer/Process/Filament presets (%d/%d), Auto Check Material
- Bed/Y-axis mass and force limits, Software Update, Current Version

UI labels and dialogs:
- Filter, Recommend, Old version, Operation, High Temp, Saving
- Nothing selected, Filament Manager, Skin/Skeleton infill pattern
- New Beta Available, Don't show Beta updates, Separate config folder
- File chooser dialogs, error messages, TPU warning

Author: BenJule