feat: track NH broadband install lifecycle (#533)

docs/nh-broadband-install-request.example.yaml

@@ -11,6 +11,31 @@ service:
 
 desired_plan: residential-fiber
 
+availability:
+  status: pending
+  checked_at: ""
+  notes: "Pending exact-address lookup on nhbroadband.com"
+
+pricing:
+  monthly_cost_usd:
+  install_fee_usd:
+  quoted_at: ""
+  notes: "Pending live quote from NH Broadband"
+
+appointment:
+  scheduled_for: ""
+  window: ""
+  confirmation_number: ""
+  installer_access_notes: "Driveway condition note pending"
+
+post_install:
+  speed_test:
+    download_mbps:
+    upload_mbps:
+    latency_ms:
+    tested_at: ""
+    notes: "Populate after installation completes"
+
 call_log:
   - timestamp: "2026-04-15T14:30:00Z"
     outcome: no_answer