feat(finance): Layer 2 — property equity integrated into Net Worth (#30)

* feat(finance): Layer 2 — property equity flows into Net Worth

- NetWorthData gains PropertyValueCents, LoanBalanceCents, PropertyEquityCents
- NetWorth handler fetches properties + loans; adds equity to current snapshot
  and uses amortisation formula to compute historical loan balances per month,
  so the chart reflects how equity grew as loans were paid down
- Dashboard NetWorthCents now includes property equity
- loanBalanceAt() helper: B_n = P*(1+r)^n - (M/r)*((1+r)^n - 1)
- networth.html: inline breakdown row in hero card (cash / portfolio / equity),
  new "Property equity" breakdown card (value − loans), chart gains a dashed
  red "Loans outstanding" line when properties are present

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

* fix(property): resolve template, image pull, and build issues

- Fix parseTmpl missing base.html causing "base.html is undefined" error
- Change imagePullPolicy to IfNotPresent for local k3d dev workflow
- Add SERVICE_NAME to Makefile so make build-deploy uses correct image name

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

---------

Co-authored-by: Gonçalo Rodrigues <guga@Goncalos-MacBook-Pro.local>
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/finance/services/api/Makefile

@@ -1,2 +1,3 @@
-PROJECT_ROOT := ../../../../
+PROJECT_ROOT  := ../../../../
+SERVICE_NAME  := finance-api
 include ../../../../infrastructure/Makefile/service.mk

apps/finance/services/api/k8s/deployment.yaml

@@ -20,7 +20,7 @@ spec:
       containers:
         - name: api
           image: git.homelab.local/admin/finance-api:latest
-          imagePullPolicy: Always
+          imagePullPolicy: IfNotPresent
           ports:
             - name: http
               containerPort: 8080

apps/finance/services/api/main/handler.go

@@ -689,6 +689,22 @@ func (h *Handler) Dashboard(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 
+	// ── Property equity (for net worth card on dashboard) ───────────────
+	var dashPropertyEquity int64
+	if dProps, err2 := h.store.getProperties(ctx, a.UserID); err2 == nil {
+		dLoans, _ := h.store.getLoans(ctx, a.UserID)
+		for _, p := range dProps {
+			if p.Status != PropertySold {
+				dashPropertyEquity += p.CurrentValueCents
+			}
+		}
+		for _, l := range dLoans {
+			if l.Status == LoanActive {
+				dashPropertyEquity -= l.BalanceCents
+			}
+		}
+	}
+
 	// ── Alerts ──────────────────────────────────────────────────────────
 	var alerts []Alert
 
@@ -792,7 +808,7 @@ func (h *Handler) Dashboard(w http.ResponseWriter, r *http.Request) {
 		PortfolioPCLCents:            portfolioPCLCents,
 		PortfolioHoldings:            portfolioHoldings,
 		PortfolioPricesAvailable:     portfolioPricesAvailable,
-		NetWorthCents:                portfolioValueCents + running,
+		NetWorthCents:                portfolioValueCents + running + dashPropertyEquity,
 		Alerts:                       alerts,
 	})
 }
@@ -2140,17 +2156,56 @@ func (h *Handler) NetWorth(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 
-	netWorthCents := cashCents + portfolioCents
+	// ── Property equity ──────────────────────────────────────────────────────────
+	var propertyValueCents, loanBalanceCents int64
+	props, _ := h.store.getProperties(ctx, a.UserID)
+	loans, _ := h.store.getLoans(ctx, a.UserID)
 
-	// build history points — each month: cash snapshot + portfolio (we only have current portfolio)
+	for _, p := range props {
+		if p.Status != PropertySold {
+			propertyValueCents += p.CurrentValueCents
+		}
+	}
+	for _, l := range loans {
+		if l.Status == LoanActive {
+			loanBalanceCents += l.BalanceCents
+		}
+	}
+	propertyEquityCents := propertyValueCents - loanBalanceCents
+	netWorthCents := cashCents + portfolioCents + propertyEquityCents
+
+	// build history points — cash snapshot + portfolio + property equity (amortised)
 	var history []NetWorthPoint
 	for _, m := range months {
 		cash := monthCash[m]
+
+		// For each month in history, compute what the loan balance was at that point
+		// using standard amortisation: B_n = P*(1+r)^n - (M/r)*((1+r)^n - 1)
+		histLoanBalance := int64(0)
+		for _, l := range loans {
+			if l.Status != LoanActive {
+				continue
+			}
+			t, _ := time.Parse("2006-01", m)
+			monthsElapsed := monthsBetween(l.StartDate, t)
+			if monthsElapsed < 0 {
+				// loan didn't exist yet — exclude its balance from this month
+				continue
+			}
+			monthly := l.MonthlyPaymentCents
+			if monthly == 0 {
+				monthly = loanMonthlyPayment(l.PrincipalCents, l.InterestRatePct, l.TermMonths)
+			}
+			histLoanBalance += loanBalanceAt(l.PrincipalCents, l.InterestRatePct, monthly, monthsElapsed)
+		}
+		// property value is static (current estimate — we don't have historical valuations)
+		histEquity := propertyValueCents - histLoanBalance
+
 		history = append(history, NetWorthPoint{
 			Month:      m,
-			AssetCents: cash + portfolioCents,
+			AssetCents: cash + portfolioCents + propertyValueCents,
-			LiabCents:  0,
+			LiabCents:  histLoanBalance,
-			NetCents:   cash + portfolioCents,
+			NetCents:   cash + portfolioCents + histEquity,
 		})
 	}
 
@@ -2162,6 +2217,9 @@ func (h *Handler) NetWorth(w http.ResponseWriter, r *http.Request) {
 		CashCents:                cashCents,
 		PortfolioCents:           portfolioCents,
 		CreditCents:              0,
+		PropertyValueCents:       propertyValueCents,
+		LoanBalanceCents:         loanBalanceCents,
+		PropertyEquityCents:      propertyEquityCents,
 		NetWorthCents:            netWorthCents,
 		PortfolioPricesAvailable: pricesAvailable,
 		History:                  history,

apps/finance/services/api/main/handler_property.go

@@ -12,7 +12,7 @@ import (
 	"go.mongodb.org/mongo-driver/v2/bson"
 )
 
-var propertyTmpl = parseTmpl("templates/property.html")
+var propertyTmpl = parseTmpl("templates/base.html", "templates/property.html")
 
 // ── Amortization helpers ──────────────────────────────────────────────────────
 
@@ -114,6 +114,28 @@ func toPropertyView(p Property, allLoans []Loan) PropertyView {
 	}
 }
 
+// loanBalanceAt returns the outstanding balance after n monthly payments.
+// Formula: B_n = P*(1+r)^n - (M/r)*((1+r)^n - 1)
+func loanBalanceAt(principalCents int64, annualRatePct float64, monthlyPaymentCents int64, monthsElapsed int) int64 {
+	if monthsElapsed <= 0 {
+		return principalCents
+	}
+	if annualRatePct == 0 {
+		b := principalCents - monthlyPaymentCents*int64(monthsElapsed)
+		if b < 0 {
+			return 0
+		}
+		return b
+	}
+	r := annualRatePct / 12 / 100
+	factor := math.Pow(1+r, float64(monthsElapsed))
+	balance := float64(principalCents)*factor - (float64(monthlyPaymentCents)/r)*(factor-1)
+	if balance < 0 {
+		return 0
+	}
+	return int64(math.Round(balance))
+}
+
 // ── Handler ───────────────────────────────────────────────────────────────────
 
 func (h *Handler) Properties(w http.ResponseWriter, r *http.Request) {

apps/finance/services/api/main/models.go

@@ -408,16 +408,19 @@ type NetWorthPoint struct {
 }
 
 type NetWorthData struct {
-	UserID   string
+	UserID string
-	Email    string
+	Email  string
-	Title    string
+	Title  string
-	Route    string
+	Route  string
 
 	// current snapshot
-	CashCents      int64 // running balance of all non-credit accounts
+	CashCents           int64 // running balance of all non-credit accounts
-	PortfolioCents int64 // market value (or cost basis)
+	PortfolioCents      int64 // market value (or cost basis)
-	CreditCents    int64 // total outstanding on credit accounts (positive = owed)
+	CreditCents         int64 // total outstanding on credit accounts (positive = owed)
-	NetWorthCents  int64 // cash + portfolio − credit
+	PropertyValueCents  int64 // sum of current value of non-sold properties
+	LoanBalanceCents    int64 // sum of active loan balances
+	PropertyEquityCents int64 // PropertyValueCents - LoanBalanceCents
+	NetWorthCents       int64 // cash + portfolio + propertyEquity − credit
 
 	PortfolioPricesAvailable bool
 

apps/finance/services/api/main/templates/networth.html

@@ -17,6 +17,16 @@
   <div class="animate-counter {{if lt $d.NetWorthCents 0}}negative{{else}}positive{{end}}"
        style="font-size:42px; font-weight:500; letter-spacing:-1.5px; line-height:1;"
        data-target="{{$d.NetWorthCents}}" data-prefix="€">€0.00</div>
+  <div style="margin-top:14px; display:flex; flex-wrap:wrap; gap:18px; font-size:13px; color:var(--text3);">
+    <span>💵 Cash <strong style="color:var(--text2);">€{{cents $d.CashCents}}</strong></span>
+    <span>📈 Portfolio <strong style="color:var(--text2);">€{{cents $d.PortfolioCents}}</strong></span>
+    {{if $d.PropertyValueCents}}
+    <span>🏠 Property equity <strong style="color:var(--text2);">€{{cents $d.PropertyEquityCents}}</strong></span>
+    {{end}}
+    {{if $d.CreditCents}}
+    <span>💳 Credit <strong style="color:var(--red);">-€{{cents $d.CreditCents}}</strong></span>
+    {{end}}
+  </div>
 </div>
 
 <!-- Breakdown cards -->
@@ -40,6 +50,17 @@
     {{end}}
   </div>
 
+  {{if $d.PropertyValueCents}}
+  <div class="card value-card animate-on-scroll">
+    <h2>Property equity</h2>
+    <div class="value animate-counter {{if lt $d.PropertyEquityCents 0}}negative{{else}}positive{{end}}"
+         data-target="{{$d.PropertyEquityCents}}" data-prefix="€">€0.00</div>
+    <p style="font-size:12px; color:var(--text3); margin-top:6px;">
+      €{{cents $d.PropertyValueCents}} value − €{{cents $d.LoanBalanceCents}} loans
+    </p>
+  </div>
+  {{end}}
+
   {{if $d.CreditCents}}
   <div class="card value-card animate-on-scroll">
     <h2>Credit / liabilities</h2>
@@ -62,37 +83,61 @@
 
 <script>
 (function() {
-  const labels = [{{range $d.History}}"{{.Month}}",{{end}}];
+  const labels   = [{{range $d.History}}"{{.Month}}",{{end}}];
-  const data   = [{{range $d.History}}{{.NetCents}},{{end}}];
+  const netData  = [{{range $d.History}}{{.NetCents}},{{end}}];
-  const ctx = document.getElementById('nw-chart').getContext('2d');
+  const cashData = [{{range $d.History}}{{.AssetCents}},{{end}}]; // assets (cash+portfolio+property)
+  const liabData = [{{range $d.History}}{{.LiabCents}},{{end}}]; // loan balances
+  const hasProperty = {{if $d.PropertyValueCents}}true{{else}}false{{end}};
+
+  const ctx    = document.getElementById('nw-chart').getContext('2d');
   const isDark = document.documentElement.getAttribute('data-theme') === 'dark';
-  const accent = getComputedStyle(document.documentElement).getPropertyValue('--accent').trim() || '#6979f8';
+  const style  = getComputedStyle(document.documentElement);
-  const green  = getComputedStyle(document.documentElement).getPropertyValue('--green').trim()  || '#4ade80';
+  const accent = style.getPropertyValue('--accent').trim()  || '#6979f8';
+  const green  = style.getPropertyValue('--green').trim()   || '#4ade80';
+  const red    = style.getPropertyValue('--red').trim()     || '#f87171';
+  const teal   = '#14b8a6';
+  const pts    = netData.length > 24 ? 0 : 3;
+
+  const datasets = [{
+    label: 'Net Worth',
+    data: netData.map(v => v / 100),
+    borderColor: accent,
+    backgroundColor: isDark ? 'rgba(105,121,248,0.07)' : 'rgba(67,85,232,0.05)',
+    fill: true,
+    tension: 0.35,
+    pointRadius: pts,
+    pointHoverRadius: 5,
+    borderWidth: 2.5,
+    order: 0,
+  }];
+
+  if (hasProperty) {
+    datasets.push({
+      label: 'Loans outstanding',
+      data: liabData.map(v => -(v / 100)),
+      borderColor: red,
+      backgroundColor: isDark ? 'rgba(248,113,113,0.06)' : 'rgba(239,68,68,0.04)',
+      fill: true,
+      tension: 0.35,
+      pointRadius: 0,
+      pointHoverRadius: 4,
+      borderWidth: 1.5,
+      borderDash: [4, 3],
+      order: 1,
+    });
+  }
 
   new Chart(ctx, {
     type: 'line',
-    data: {
+    data: { labels, datasets },
-      labels,
-      datasets: [{
-        label: 'Net Worth (€)',
-        data: data.map(v => v / 100),
-        borderColor: accent,
-        backgroundColor: isDark ? 'rgba(105,121,248,0.08)' : 'rgba(67,85,232,0.06)',
-        fill: true,
-        tension: 0.35,
-        pointRadius: data.length > 24 ? 0 : 3,
-        pointHoverRadius: 5,
-        borderWidth: 2,
-      }]
-    },
     options: {
       responsive: true,
       interaction: { intersect: false, mode: 'index' },
       plugins: {
-        legend: { display: false },
+        legend: { display: hasProperty, labels: { color: isDark ? '#8892b0' : '#64748b', boxWidth: 12, font: { size: 12 } } },
         tooltip: {
           callbacks: {
-            label: ctx => '€' + ctx.parsed.y.toLocaleString('pt-PT', {minimumFractionDigits:2})
+            label: c => c.dataset.label + ': €' + Math.abs(c.parsed.y).toLocaleString('pt-PT', {minimumFractionDigits:2})
           }
         }
       },