security: fix 27 vulnerabilities + UI integration (Issues tab, project nav, validation)

Security fixes (27 vulnerabilities across 20 files):
CRITICAL:
- MediaManager: whitelist mediable types prevents RCE via class instantiation
- MediaManager/OfflineSyncController: IDOR fixes, remove Auth::id()??1 fallback
- ClientProjects: verify project ownership on all mutations (IDOR)
- CompanyManagement: Admin role check on mount() and mutations (auth bypass)
- ProjectMap: scope feature/template lookups to current project (IDOR x5)
- PhaseList/TemplateManager/LayerManager: scope mutations to owned resources (IDOR)
- ProjectEditTabs: Gate::authorize on mount() and updateProject()
- routes/web.php: reports routes moved inside can:manage all middleware (auth bypass)

MEDIUM:
- layer-manager: escapeHtml() on Leaflet popup interpolations (XSS)
- MediaManager: server-side MIME validation + 50MB limit
- ProjectList/ProjectUsers/ProjectCompanies/PhaseProgress: auth checks added
- AdminUsers/ReportsDashboard/ExportController: role/permission checks added

LOW:
- config/session.php: secure cookie tied to production env
- OfflineSyncController: sanitize storage path (path traversal)

UI integration:
- project-map: Issues tab (4th) with open-count badge
- project-map: project navigation bar (Dashboard/Map/Gantt/Report/Issues)
- project-dashboard: action buttons for Map/Gantt/Report/Issues
- project-form: validation error summary + per-field @error spans
- template-manager: validation error display

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

app/Livewire/ProjectEditTabs.php

@@ -4,6 +4,7 @@ namespace App\Livewire;
 
 use Livewire\Component;
 use App\Models\Project;
+use Illuminate\Support\Facades\Gate;
 
 class ProjectEditTabs extends Component
 {
@@ -12,6 +13,7 @@ class ProjectEditTabs extends Component
 
     public function mount(Project $project)
     {
+        Gate::authorize('edit projects', $project);
         $this->project = $project;
     }
 
@@ -29,8 +31,9 @@ class ProjectEditTabs extends Component
 
     public function updateProject()
     {
+        Gate::authorize('edit projects', $this->project);
         $this->project->save();
-        
+
         session()->flash('message', __('Project updated successfully.'));
         $this->dispatch('project-updated');
     }