feat: implement soft delete, task editing fixes, and UI improvements

Backend:
- Add soft delete for spaces and projects (is_active flag)
- Add status_id and assignee_id to TaskUpdate schema
- Fix task PATCH endpoint to update status and assignee
- Add validation for assignee_id and status_id in task updates
- Fix health service to count tasks with "Blocked" status as blockers
- Filter out deleted spaces/projects from health dashboard
- Add workload cache invalidation on assignee changes

Frontend:
- Add delete confirmation dialogs for spaces and projects
- Fix UserSelect to display selected user name (valueName prop)
- Fix task detail modal to refresh data after save
- Enforce 2-level subtask depth limit in UI
- Fix timezone bug in date formatting (use local timezone)
- Convert NotificationBell from Tailwind to inline styles
- Add i18n translations for health, workload, settings pages
- Add parent_task_id to Task interface across components

OpenSpec:
- Archive add-delete-capability change

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

frontend/public/locales/en/health.json

@@ -11,11 +11,24 @@
     "totalProjects": "Total Projects",
     "healthy": "Healthy",
     "atRisk": "At Risk",
+    "highRisk": "High Risk",
     "critical": "Critical",
     "avgHealth": "Avg. Health",
     "withBlockers": "With Blockers",
     "delayed": "Delayed"
   },
+  "calculation": {
+    "title": "Health Score Calculation",
+    "formula": "Starting score: 100, reduced by:",
+    "blockers": "Blockers: -10 per item (max -30)",
+    "overdue": "Overdue tasks: -5 per item (max -30)",
+    "completion": "Low completion: up to -20 if below 50%",
+    "thresholds": "Risk Level Thresholds:",
+    "lowRisk": "Low Risk (Healthy): ≥ 80",
+    "mediumRisk": "Medium Risk: 60-79",
+    "highRiskLevel": "High Risk: 40-59",
+    "criticalRisk": "Critical: < 40"
+  },
   "sort": {
     "label": "Sort by",
     "riskHigh": "Risk: High to Low",
@@ -36,7 +49,29 @@
     "delayed": "Delayed",
     "ahead": "Ahead",
     "overBudget": "Over Budget",
-    "underBudget": "Under Budget"
+    "underBudget": "Under Budget",
+    "atRisk": "At Risk"
+  },
+  "resourceStatus": {
+    "adequate": "Adequate",
+    "constrained": "Constrained",
+    "overloaded": "Overloaded"
+  },
+  "card": {
+    "health": "Health",
+    "schedule": "Schedule",
+    "resources": "Resources",
+    "owner": "Owner",
+    "taskProgress": "Task Progress",
+    "blockers": "Blockers",
+    "overdue": "Overdue",
+    "complete": "Complete"
+  },
+  "riskLevel": {
+    "low": "Low Risk",
+    "medium": "Medium Risk",
+    "high": "High Risk",
+    "critical": "Critical"
   },
   "indicators": {
     "title": "Health Indicators",