Make Resend from-address config-only; drop credential status rows

The Settings page no longer renders the Resend From Address input or any
of the read-only "Set in config.toml" credential status rows (Apify key,
eBay id/secret, ntfy auth, Resend key). Those rows looked like editable
inputs but were dead text, and duplicated what the Test buttons verify
more authoritatively.

- resend_from is now sourced only from config.toml ([resend] from); it is
  removed from settingsKeys, the test-Resend handler, the scheduler email
  client, and the schema seed.
- Removed the credStatus templ component, the CredentialStatus field on
  SettingsData, and the credentialStatus() handler helper.

templates/settings.templ

@@ -8,12 +8,8 @@ import (
 
 type SettingsData struct {
 	Page
-	Values map[string]string
-	// CredentialStatus maps each secret settings key to a human-readable
-	// status ("Saved in settings", "Set in config.toml", "Not set"). Secret
-	// values are never rendered into the form itself.
-	CredentialStatus map[string]string
-	IsAdmin          bool
+	Values  map[string]string
+	IsAdmin bool
 	Users          []models.User
 	TestNtfyOK     string
 	TestApifyOK    string
@@ -48,16 +44,6 @@ func (d SettingsData) EbayLimitReached() bool {
 	return d.EbayDailyLimit > 0 && d.EbayUsedToday >= d.EbayDailyLimit
 }
 
-// credStatus renders the "Saved in settings / Set in config.toml / Not set"
-// indicator for a secret field without ever printing the secret itself.
-templ credStatus(d SettingsData, key string) {
-	if s := d.CredentialStatus[key]; s != "" {
-		<div class="v-muted text-xs mt-1">
-			Status: { s }
-		</div>
-	}
-}
-
 templ settingsBody(d SettingsData) {
 	<div class="space-y-8 max-w-3xl">
 		<div>
@@ -72,18 +58,6 @@ templ settingsBody(d SettingsData) {
 			</div>
 			<form method="post" action="/settings" class="space-y-4">
 				@CSRFInput(d.CSRFToken)
-				<div>
-					<label class="v-label">Apify API Key</label>
-					@credStatus(d, "apify_api_key")
-				</div>
-				<div class="border-t border-white/10 pt-4">
-					<label class="v-label">eBay App ID (Client ID)</label>
-					@credStatus(d, "ebay_client_id")
-				</div>
-				<div>
-					<label class="v-label">eBay Cert ID (Client Secret)</label>
-					@credStatus(d, "ebay_client_secret")
-				</div>
 				<div>
 					<label class="v-label">eBay Daily Call Limit</label>
 					<input class="v-input font-mono" name="ebay_daily_call_limit" type="number" value={ d.Values["ebay_daily_call_limit"] } placeholder="5000 (blank uses config default)"/>
@@ -107,10 +81,6 @@ templ settingsBody(d SettingsData) {
 					<label class="v-label">Ntfy Default Topic</label>
 					<input class="v-input" name="ntfy_default_topic" value={ d.Values["ntfy_default_topic"] }/>
 				</div>
-				<div>
-					<label class="v-label">Ntfy Auth (user / password)</label>
-					@credStatus(d, "ntfy_auth")
-				</div>
 				<div>
 					<label class="v-label">Global Poll Interval (minutes)</label>
 					<input class="v-input font-mono" name="global_poll_interval_minutes" type="number" value={ d.Values["global_poll_interval_minutes"] }/>
@@ -119,15 +89,6 @@ templ settingsBody(d SettingsData) {
 					<label class="v-label">Match Confidence Threshold</label>
 					<input class="v-input font-mono" name="match_confidence_threshold" type="number" min="0" max="1" step="0.05" value={ d.Values["match_confidence_threshold"] }/>
 				</div>
-				<div class="border-t border-white/10 pt-4">
-					<label class="v-label">Resend API Key</label>
-					@credStatus(d, "resend_api_key")
-				</div>
-				<div>
-					<label class="v-label">Resend From Address</label>
-					<input class="v-input" name="resend_from" value={ d.Values["resend_from"] } placeholder="Veola &lt;veola@yourdomain.com&gt;"/>
-					<div class="v-muted text-xs mt-1">Used for deal-alert and weekly-digest email. Domain must be verified in Resend.</div>
-				</div>
 				<div class="border-t border-white/10 pt-4">
 					<label class="v-label">Estimated Apify Cost per Call (USD)</label>
 					<input class="v-input font-mono" name="apify_cost_per_call" type="number" min="0" step="0.001" value={ d.Values["apify_cost_per_call"] }/>