Add USB, Notifications, Network plugins and reusable EmployeeSearch component

New Plugins:
- USB plugin: Device checkout/checkin with employee lookup, checkout history
- Notifications plugin: Announcements with types, scheduling, shopfloor display
- Network plugin: Network device management with subnets and VLANs
- Equipment and Computers plugins: Asset type separation

Frontend:
- EmployeeSearch component: Reusable employee lookup with autocomplete
- USB views: List, detail, checkout/checkin modals
- Notifications views: List, form with recognition mode
- Network views: Device list, detail, form
- Calendar view with FullCalendar integration
- Shopfloor and TV dashboard views
- Reports index page
- Map editor for asset positioning
- Light/dark mode fixes for map tooltips

Backend:
- Employee search API with external lookup service
- Collector API for PowerShell data collection
- Reports API endpoints
- Slides API for TV dashboard
- Fixed AppVersion model (removed BaseModel inheritance)
- Added checkout_name column to usbcheckouts table

Styling:
- Unified detail page styles
- Improved pagination (page numbers instead of prev/next)
- Dark/light mode theme improvements

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

shopdb/core/models/application.py

@@ -64,7 +64,7 @@ class Application(BaseModel):
         return f"<Application {self.appname}>"
 
 
-class AppVersion(BaseModel):
+class AppVersion(db.Model):
     """Application version tracking."""
     __tablename__ = 'appversions'
 
@@ -74,6 +74,7 @@ class AppVersion(BaseModel):
     releasedate = db.Column(db.Date)
     notes = db.Column(db.String(255))
     dateadded = db.Column(db.DateTime, default=db.func.now())
+    isactive = db.Column(db.Boolean, default=True)
 
     # Relationships
     application = db.relationship('Application', back_populates='versions')
@@ -84,6 +85,18 @@ class AppVersion(BaseModel):
         db.UniqueConstraint('appid', 'version', name='uq_app_version'),
     )
 
+    def to_dict(self):
+        """Convert to dictionary."""
+        return {
+            'appversionid': self.appversionid,
+            'appid': self.appid,
+            'version': self.version,
+            'releasedate': self.releasedate.isoformat() if self.releasedate else None,
+            'notes': self.notes,
+            'dateadded': self.dateadded.isoformat() + 'Z' if self.dateadded else None,
+            'isactive': self.isactive
+        }
+
     def __repr__(self):
         return f"<AppVersion {self.application.appname if self.application else self.appid} v{self.version}>"