Add descriptive error messages across all API routes and toast notifications on client pages

- 86 catch blocks in 49 API route files now return the actual error message via error.message
- 14 campaign/lead/config catch blocks that lacked console.error now log errors
- 17 client pages/components now show toast.error notifications on API failures
- Silent .catch(() => {}) and finally-only try blocks now surface errors to users

src/app/(dashboard)/proposals/[id]/page.tsx

@@ -15,6 +15,7 @@ import {
   SelectTrigger,
   SelectValue,
 } from "@/components/ui/select"
+import { toast } from "sonner"
 
 export default function ProposalDetailPage() {
   const { id } = useParams<{ id: string }>()
@@ -35,6 +36,7 @@ export default function ProposalDetailPage() {
       setProposal(await pRes.json())
       setStatuses(await sRes.json())
     } catch (e) {
+      toast.error("Failed to load proposal")
       console.error("Failed to load proposal", e)
     } finally {
       setLoading(false)
@@ -44,12 +46,17 @@ export default function ProposalDetailPage() {
   useEffect(() => { fetchProposal() }, [fetchProposal])
 
   const updateStatus = async (statusId: string) => {
-    await fetch(`/api/proposals/${id}`, {
-      method: "PATCH",
-      headers: { "Content-Type": "application/json" },
-      body: JSON.stringify({ statusId }),
-    })
-    fetchProposal()
+    try {
+      await fetch(`/api/proposals/${id}`, {
+        method: "PATCH",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify({ statusId }),
+      })
+      fetchProposal()
+    } catch (e) {
+      console.error("Failed to update proposal status", e)
+      toast.error("Failed to update proposal status")
+    }
   }
 
   const handleSign = async () => {
@@ -62,6 +69,9 @@ export default function ProposalDetailPage() {
         body: JSON.stringify({ name: signName, email: signEmail }),
       })
       if (res.ok) fetchProposal()
+    } catch (e) {
+      console.error("Failed to sign proposal", e)
+      toast.error("Failed to sign proposal")
     } finally {
       setSigning(false)
     }

src/app/(dashboard)/proposals/new/page.tsx

@@ -14,6 +14,7 @@ import {
   SelectTrigger,
   SelectValue,
 } from "@/components/ui/select"
+import { toast } from "sonner"
 
 interface LineItem {
   id: string
@@ -39,8 +40,8 @@ export default function NewProposalPage() {
   const [saving, setSaving] = useState(false)
 
   useEffect(() => {
-    fetch("/api/leads?limit=100").then((r) => r.json()).then(setLeads).catch(() => {})
-    fetch("/api/customers?limit=100").then((r) => r.json()).then(setCustomers).catch(() => {})
+    fetch("/api/leads?limit=100").then((r) => r.json()).then(setLeads).catch((e) => { console.error("Failed to load leads", e); toast.error("Failed to load leads") })
+    fetch("/api/customers?limit=100").then((r) => r.json()).then(setCustomers).catch((e) => { console.error("Failed to load customers", e); toast.error("Failed to load customers") })
   }, [])
 
   const addItem = () => {
@@ -107,6 +108,7 @@ export default function NewProposalPage() {
 
       router.push(`/proposals/${data.id}`)
     } catch (e) {
+      toast.error("Failed to create proposal")
       console.error("Failed to create proposal", e)
     } finally {
       setSaving(false)

src/app/(dashboard)/proposals/page.tsx

@@ -15,6 +15,7 @@ import {
   SelectTrigger,
   SelectValue,
 } from "@/components/ui/select"
+import { toast } from "sonner"
 
 export default function ProposalsPage() {
   const router = useRouter()
@@ -31,12 +32,12 @@ export default function ProposalsPage() {
     fetch(`/api/proposals?${params}`)
       .then((r) => r.json())
       .then(setProposals)
-      .catch(() => {})
+      .catch((e) => { console.error("Failed to load proposals", e); toast.error("Failed to load proposals") })
       .finally(() => setLoading(false))
   }, [search, statusFilter])
 
   useEffect(() => {
-    fetch("/api/proposal-statuses").then((r) => r.json()).then(setStatuses).catch(() => {})
+    fetch("/api/proposal-statuses").then((r) => r.json()).then(setStatuses).catch((e) => { console.error("Failed to load proposal statuses", e); toast.error("Failed to load proposal statuses") })
   }, [])
 
   const formatCurrency = (n: number) => n ? `R${Number(n).toLocaleString()}` : "R0"