fix: EditEvent returns standalone form fragment, not full page

- Edit button now shows inline form with pre-filled values
- Cancel button hides the form again
- Computes sample claim from existing exchange rate
- No full-page rendering issues

internal/handlers/events.go

@@ -6,6 +6,8 @@ package handlers
 
 import (
 	"database/sql"
+	"fmt"
+	"html/template"
 	"log"
 	"net/http"
 	"strconv"
@@ -264,7 +266,7 @@ func (h *EventHandler) ViewEventExpenses(w http.ResponseWriter, r *http.Request)
 // GET /events/{id}/edit — EditEvent
 // ---------------------------------------------------------------------------
 
-// EditEvent returns the event edit form pre-filled with current event data.
+// EditEvent returns the event edit form fragment pre-filled with current data.
 func (h *EventHandler) EditEvent(w http.ResponseWriter, r *http.Request) {
 	eventID := chi.URLParam(r, "id")
 	event, err := database.GetEventByID(h.DB, eventID)
@@ -273,20 +275,51 @@ func (h *EventHandler) EditEvent(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	tmpl := getTemplate("dashboard.html")
-	data := map[string]interface{}{
-		"Event":          event,
-		"Editing":        true,
-		"Events":         []database.Event{},
-		"BaseCurrency":   event.BaseCurrency,
-		"ExchangeRate":   event.ExchangeRate,
-		"LastSampleRcpt": "",
-		"LastSampleClm":  "",
-	}
-	if err := tmpl.Execute(w, data); err != nil {
-		log.Printf("ERROR [%s] handlers: EditEvent: execute template: %v",
-			time.Now().Format(time.RFC3339), err)
+	// Build a slug for the sample receipt currency (use base currency as default).
+	rcptCur := event.BaseCurrency
+	if rcptCur == "" {
+		rcptCur = "KES"
 	}
+
+	// Compute a rough reverse sample from the exchange rate:
+	// rate = claim / receipt → sample_receipt = 1000, sample_claim = 1000 * rate
+	sampleClm := event.ExchangeRate * 1000
+
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+	fmt.Fprintf(w, `<div class="card" style="padding: 1rem;">
+	<h3 style="margin-bottom: 1rem;">Edit Event</h3>
+	<form hx-put="/events/%s" hx-target="body" hx-push-url="true">
+		<div class="form-group">
+			<label class="form-label">Event</label>
+			<input type="text" name="name" value="%s" placeholder="Event name">
+		</div>
+		<div class="form-group">
+			<label class="form-label">Claim Currency</label>
+			<input type="text" name="base_currency" value="%s" required maxlength="3" style="text-transform: uppercase;">
+		</div>
+		<div style="background: #064e3b; border: 1px solid #065f46; border-radius: 0.5rem; padding: 0.75rem; margin-bottom: 0.5rem;">
+			<div style="font-size: 0.8rem; font-weight: 600; color: #6ee7b7; margin-bottom: 0.5rem;">Conversion Sample</div>
+			<p style="font-size: 0.75rem; color: var(--color-text-muted); margin-bottom: 0.5rem;">Update the sample to recalculate the rate.</p>
+			<div class="form-row">
+				<div class="form-group">
+					<label class="form-label">Receipt Amount</label>
+					<input type="number" name="sample_receipt_amount" value="1000" step="0.01" min="0.01" required>
+				</div>
+				<div class="form-group" style="flex: 0 0 110px;">
+					<label class="form-label">Currency</label>
+					<input type="text" name="sample_receipt_currency" value="%s" required maxlength="3" style="text-transform: uppercase;">
+				</div>
+			</div>
+			<div class="form-group">
+				<label class="form-label">Converted amount</label>
+				<input type="number" name="sample_claim_amount" value="%.2f" step="0.01" min="0.01" required>
+			</div>
+		</div>
+		<button type="submit" class="btn btn-primary btn-block">Save Changes</button>
+		<button type="button" class="btn btn-secondary btn-block" style="margin-top: 0.5rem;"
+				onclick="document.getElementById('create-event-form').innerHTML='';document.getElementById('create-event-form').classList.add('hidden')">Cancel</button>
+	</form>
+</div>`, event.ID, template.HTMLEscapeString(event.Name), template.HTMLEscapeString(event.BaseCurrency), template.HTMLEscapeString(rcptCur), sampleClm)
 }
 
 // ---------------------------------------------------------------------------