fix: render platform fee separately in Cost line, not folded into ETH

Two related Copilot review findings:
- Read-only deployed runs were rendering "0.00000X ETH ($0.02)" — the
  flat platform fee converted to ETH-equivalent looked like gas, even
  though no on-chain action ran. Misleading.
- When Moralis isn't configured, the platform fee silently disappeared
  from the rendered Cost line because USD→ETH conversion couldn't
  proceed. The user's total understated by $0.02 with no signal.

Fix: stop folding executionFee into the native-ETH amount. Always emit
it as its own USD-denominated TokenTotal entry; renderer special-cases
Unit=="USD" to emit "$X platform fee".

Resulting renders:
  ⛽ Cost: 0.000003 ETH ($0.01), $0.02 platform fee     (priced + on-chain)
  ⛽ Cost: 0.000003 ETH ($?), $0.02 platform fee        (unpriced)
  ⛽ Cost: $0.02 platform fee                           (read-only)

Attribution stays clear: gas in ETH, value-fee per token, platform fee
in dollars. The platform fee is shown even without Moralis configured,
since its USD value is known directly.

Tests: TestFormatTelegramFromStructured_PlatformFeeOnly (read-only path)
and TestFormatTelegramFromStructured_NoPriceService (unpriced path).
Existing RunnerAndFees test updated to expect the separate platform fee.

Author: will-dz

core/taskengine/summarizer_deterministic.go

@@ -1549,11 +1549,12 @@ func buildTotalsFromVM(vm *VM, fees *FeesInfo) []*TokenTotal {
 	}
 	weiPerEth := new(big.Float).SetInt(new(big.Int).Exp(big.NewInt(10), big.NewInt(18), nil))
 	nativeEth := new(big.Float).Quo(new(big.Float).SetInt(gasWei), weiPerEth)
-	if fees.ExecutionFee != nil && fees.ExecutionFee.Amount != "" && nativePriceUSD != nil {
-		if usd, ok := new(big.Float).SetString(fees.ExecutionFee.Amount); ok {
-			nativeEth.Add(nativeEth, new(big.Float).Quo(usd, nativePriceUSD))
-		}
-	}
+	// Platform (execution) fee is rendered as its own USD entry below — NOT
+	// folded into the native-ETH amount. Keeping it separate ensures (a) the
+	// fee is shown even when no price service is configured, (b) read-only
+	// runs that paid only the platform fee don't display a misleading
+	// "0.00000X ETH" gas-equivalent line, and (c) attribution stays clear
+	// (this much was gas, this much was the platform charge).
 
 	// 2. Value-fee per-token aggregation. tier_percentage × tx_value in each
 	//    transferred token's units, summed across loop iterations.
@@ -1611,6 +1612,18 @@ func buildTotalsFromVM(vm *VM, fees *FeesInfo) []*TokenTotal {
 		}
 		out = append(out, entry)
 	}
+
+	// Platform (execution) fee — appended last as a USD-denominated entry.
+	// Renderer special-cases Unit=="USD" to emit "$X platform fee" instead of
+	// the standard token-amount format. Always shown when non-zero so the
+	// user sees what they paid even when no price service is configured.
+	if fees.ExecutionFee != nil {
+		amount := trimTrailingZeros(strings.TrimSpace(fees.ExecutionFee.Amount))
+		if amount != "" && amount != "0" {
+			out = append(out, &TokenTotal{Amount: amount, Unit: "USD", USD: amount})
+		}
+	}
+
 	return out
 }
 

core/taskengine/summarizer_format_email.go

@@ -347,6 +347,11 @@ func buildFeesSectionHTML(s Summary) string {
 		if t == nil || t.Amount == "" || t.Amount == "0" {
 			continue
 		}
+		// USD-unit entries are the platform fee — render as "$X platform fee".
+		if t.Unit == "USD" {
+			parts = append(parts, fmt.Sprintf("$%s platform fee", html.EscapeString(t.Amount)))
+			continue
+		}
 		usd := "$?"
 		if t.USD != "" {
 			usd = "$" + t.USD

core/taskengine/summarizer_format_telegram.go

@@ -264,6 +264,12 @@ func formatTelegramCostLine(s Summary) string {
 		if t == nil || t.Amount == "" || t.Amount == "0" {
 			continue
 		}
+		// USD-unit entries are the platform fee — render as "$X platform fee"
+		// (the dollar amount is already canonical; no need for the parenthetical).
+		if t.Unit == "USD" {
+			parts = append(parts, fmt.Sprintf("$%s platform fee", html.EscapeString(t.Amount)))
+			continue
+		}
 		usd := "$?"
 		if t.USD != "" {
 			usd = "$" + t.USD

core/taskengine/summarizer_format_test.go

@@ -1035,7 +1035,8 @@ func TestFormatTelegramFromStructured_RunnerAndFees(t *testing.T) {
 		Fees: &FeesInfo{
 			ExecutionFee: &FeeAmount{Amount: "0.020000", Unit: "USD"},
 			Total: []*TokenTotal{
-				{Amount: "0.000011", Unit: "ETH", USD: "0.03"},
+				{Amount: "0.000003", Unit: "ETH", USD: "0.01"},
+				{Amount: "0.02", Unit: "USD", USD: "0.02"}, // platform fee — renders as "$0.02 platform fee"
 			},
 		},
 	}
@@ -1061,12 +1062,12 @@ func TestFormatTelegramFromStructured_RunnerAndFees(t *testing.T) {
 		t.Errorf("runner address should not be <code>-wrapped, got:\n%s", out)
 	}
 
-	// Cost line: native-token first, USD parenthetical, ⛽ leading emoji.
-	if !strings.Contains(out, "⛽ <b>Cost:</b> 0.000011 ETH ($0.03)") {
-		t.Errorf("missing multi-token Cost line in:\n%s", out)
+	// Cost line: native gas first, then platform fee as a separate "$X platform fee".
+	if !strings.Contains(out, "⛽ <b>Cost:</b> 0.000003 ETH ($0.01), $0.02 platform fee") {
+		t.Errorf("missing combined gas+platform Cost line in:\n%s", out)
 	}
-	if strings.Contains(out, "(~") || strings.Contains(out, "platform fee") || strings.Contains(out, "<b>Value fee:</b>") {
-		t.Errorf("Telegram should not render gas-units / 'platform fee' / Value fee line, got:\n%s", out)
+	if strings.Contains(out, "(~") || strings.Contains(out, "<b>Value fee:</b>") {
+		t.Errorf("Telegram should not render gas-units detail or Value fee line, got:\n%s", out)
 	}
 	if strings.Contains(out, "(cost estimated at deploy)") {
 		t.Errorf("deployed run should not show simulation placeholder, got:\n%s", out)
@@ -1081,6 +1082,55 @@ func TestFormatTelegramFromStructured_RunnerAndFees(t *testing.T) {
 	t.Logf("Telegram render:\n%s", out)
 }
 
+// TestFormatTelegramFromStructured_PlatformFeeOnly covers the read-only path:
+// no on-chain steps, only the platform fee. Renders as "$0.02 platform fee"
+// with no gas-equivalent ETH line that could be misread as gas.
+func TestFormatTelegramFromStructured_PlatformFeeOnly(t *testing.T) {
+	summary := Summary{
+		Subject:  "Run #1: Read-Only Workflow successfully completed",
+		Status:   "success",
+		Network:  "Sepolia",
+		Workflow: &WorkflowInfo{IsSimulation: false},
+		Runner:   &RunnerInfo{SmartWallet: "0x8Ee38eB323c14a1752DABDA1cca9661AEE377017"},
+		Fees: &FeesInfo{
+			ExecutionFee: &FeeAmount{Amount: "0.02", Unit: "USD"},
+			Total: []*TokenTotal{
+				{Amount: "0.02", Unit: "USD", USD: "0.02"},
+			},
+		},
+	}
+	out := FormatForMessageChannels(summary, "telegram", nil)
+	if !strings.Contains(out, "⛽ <b>Cost:</b> $0.02 platform fee") {
+		t.Errorf("expected platform-fee-only Cost line, got:\n%s", out)
+	}
+	if strings.Contains(out, " ETH (") {
+		t.Errorf("read-only run should not render an ETH line, got:\n%s", out)
+	}
+}
+
+// TestFormatTelegramFromStructured_NoPriceService covers Moralis-not-configured:
+// gas renders with $? for USD; platform fee still shows as the canonical $X.
+func TestFormatTelegramFromStructured_NoPriceService(t *testing.T) {
+	summary := Summary{
+		Subject:  "Run #1: Workflow successfully completed",
+		Status:   "success",
+		Network:  "Sepolia",
+		Workflow: &WorkflowInfo{IsSimulation: false},
+		Runner:   &RunnerInfo{SmartWallet: "0x8Ee38eB323c14a1752DABDA1cca9661AEE377017"},
+		Fees: &FeesInfo{
+			ExecutionFee: &FeeAmount{Amount: "0.02", Unit: "USD"},
+			Total: []*TokenTotal{
+				{Amount: "0.000003", Unit: "ETH", USD: ""}, // unpriced — renders "$?"
+				{Amount: "0.02", Unit: "USD", USD: "0.02"},
+			},
+		},
+	}
+	out := FormatForMessageChannels(summary, "telegram", nil)
+	if !strings.Contains(out, "⛽ <b>Cost:</b> 0.000003 ETH ($?), $0.02 platform fee") {
+		t.Errorf("expected unpriced ETH + platform fee, got:\n%s", out)
+	}
+}
+
 // TestFormatTelegramFromStructured_MultiToken_USDPlaceholder verifies the
 // multi-token comma-separated render and the "$?" placeholder for unpriceable
 // entries. Mirror of the format spec in the PRD's Rendering section.