feat(time-blocks): Add comprehensive time blocking system with contracts

- Add TimeBlock and Holiday models with recurrence support (one-time, weekly, monthly, yearly, holiday)
- Implement business-level and resource-level blocking with hard/soft block types
- Add multi-select holiday picker for bulk holiday blocking
- Add calendar overlay visualization with distinct colors:
  - Business blocks: Red (hard) / Yellow (soft)
  - Resource blocks: Purple (hard) / Cyan (soft)
- Add month view resource indicators showing 1/n width per resource
- Add yearly calendar view for block overview
- Add My Availability page for staff self-service
- Add contracts module with templates, signing flow, and PDF generation
- Update scheduler with click-to-day navigation in week view

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

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

frontend/src/i18n/locales/en.json

@@ -92,6 +92,7 @@
     "platformSettings": "Platform Settings",
     "tickets": "Tickets",
     "help": "Help",
+    "contracts": "Contracts",
     "platformGuide": "Platform Guide",
     "ticketingHelp": "Ticketing System",
     "apiDocs": "API Docs",
@@ -409,6 +410,106 @@
     "sendReply": "Send Reply",
     "ticketClosedNoReply": "This ticket is closed. If you need further assistance, please open a new support request."
   },
+  "contracts": {
+    "title": "Contracts",
+    "description": "Manage contract templates and sent contracts",
+    "templates": "Templates",
+    "allContracts": "All Contracts",
+    "createTemplate": "Create Template",
+    "createContract": "Create Contract",
+    "editTemplate": "Edit Template",
+    "viewContract": "View Contract",
+    "noTemplates": "No contract templates yet",
+    "noContracts": "No contracts yet",
+    "templateName": "Template Name",
+    "templateDescription": "Description",
+    "content": "Content",
+    "scope": {
+      "label": "Scope",
+      "customer": "Customer Agreement",
+      "appointment": "Appointment Agreement"
+    },
+    "status": {
+      "label": "Status",
+      "draft": "Draft",
+      "active": "Active",
+      "archived": "Archived",
+      "pending": "Pending Signature",
+      "signed": "Signed",
+      "expired": "Expired",
+      "voided": "Voided"
+    },
+    "expiresAfterDays": "Expires After (Days)",
+    "expiresAfterDaysHint": "Leave empty for no expiration",
+    "versionNotes": "Version Notes",
+    "versionNotesPlaceholder": "What changed in this version?",
+    "services": "Applicable Services",
+    "servicesHint": "Leave empty to apply to all services",
+    "customer": "Customer",
+    "appointment": "Appointment",
+    "service": "Service",
+    "sentAt": "Sent At",
+    "signedAt": "Signed At",
+    "expiresAt": "Expires At",
+    "actions": {
+      "send": "Send Contract",
+      "resend": "Resend Contract",
+      "void": "Void Contract",
+      "duplicate": "Duplicate Template",
+      "preview": "Preview",
+      "delete": "Delete"
+    },
+    "sendContract": {
+      "title": "Send Contract",
+      "selectCustomer": "Select Customer",
+      "selectAppointment": "Select Appointment (Optional)",
+      "selectService": "Select Service (Optional)",
+      "send": "Send",
+      "success": "Contract sent successfully",
+      "error": "Failed to send contract"
+    },
+    "voidContract": {
+      "title": "Void Contract",
+      "reason": "Reason for voiding",
+      "reasonPlaceholder": "Why is this contract being voided?",
+      "confirm": "Void Contract",
+      "success": "Contract voided successfully",
+      "error": "Failed to void contract"
+    },
+    "preview": {
+      "title": "Preview Contract",
+      "sampleData": "Using sample data for preview"
+    },
+    "signing": {
+      "title": "Sign Contract",
+      "businessName": "{{businessName}}",
+      "contractFor": "Contract for {{customerName}}",
+      "pleaseReview": "Please review and sign this contract",
+      "signerName": "Your Full Name",
+      "signerEmail": "Your Email",
+      "signatureLabel": "Sign Below",
+      "signaturePlaceholder": "Draw your signature here",
+      "clearSignature": "Clear",
+      "agreeToTerms": "I agree to the terms and conditions",
+      "submitSignature": "Submit Signature",
+      "submitting": "Submitting...",
+      "success": "Contract signed successfully!",
+      "error": "Failed to sign contract",
+      "expired": "This contract has expired",
+      "alreadySigned": "This contract has already been signed",
+      "notFound": "Contract not found",
+      "signedBy": "Signed by {{name}} on {{date}}",
+      "thankYou": "Thank you for signing!"
+    },
+    "errors": {
+      "loadFailed": "Failed to load contracts",
+      "createFailed": "Failed to create contract",
+      "updateFailed": "Failed to update contract",
+      "deleteFailed": "Failed to delete contract",
+      "sendFailed": "Failed to send contract",
+      "voidFailed": "Failed to void contract"
+    }
+  },
   "dashboard": {
     "title": "Dashboard",
     "welcome": "Welcome, {{name}}!",