feat(web): mode-aware backlog banner — stop telling manual users summaries auto-arrive

The first pilot user sat in Manual mode reading "new summaries land gradually,
check back tomorrow" — copy that only makes sense in Automatic mode. Manual mode
never auto-summarizes, so the banner promised delivery that would never come.

The list page now reads the user's summarize mode and shows mode-correct copy:
- Auto: unchanged "land gradually" backlog note.
- Manual: "new videos appear here but are not summarized automatically — use the
  Summarize button" plus a "Switch to Automatic" link to /account.
The connected-but-empty first-run state is likewise mode-aware.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

internal/web/views.templ

@@ -104,7 +104,7 @@ templ flashBanner(code string) {
 // #summary-list region; a non-HTMX request renders the whole page. flash carries
 // a one-shot notification (e.g. "connected", "registered") surfaced on arrival
 // after a POST→redirect.
-templ ListPage(b listBuckets, f Filter, stats PipelineStats, flash string, hasConnected bool, channels []string) {
+templ ListPage(b listBuckets, f Filter, stats PipelineStats, flash string, hasConnected bool, channels []string, autoSummarize bool) {
 	@Layout("Tapir — Summaries") {
 		@flashBanner(flash)
 		if hasConnected {
@@ -116,14 +116,23 @@ templ ListPage(b listBuckets, f Filter, stats PipelineStats, flash string, hasCo
 		if stats.RateLimited > 0 || stats.Pending > 0 || stats.NoText > 0 {
 			@pipelineBar(stats)
 		}
-		if stats.RateLimited+stats.Pending > 0 {
+		if (stats.RateLimited+stats.Pending) > 0 && autoSummarize {
 			<p class="pipeline-note muted">
 				Tapir fetches captions slowly on purpose, to respect YouTube's limits —
 				new summaries land gradually. Check back tomorrow.
 			</p>
 		}
+		if (stats.RateLimited+stats.Pending) > 0 && !autoSummarize {
+			<p class="pipeline-note muted">
+				You are in Manual mode: new videos appear here but are not summarized
+				automatically. Use the Summarize button on the ones you want.
+			</p>
+			<p class="pipeline-note muted">
+				<a href="/account">Switch to Automatic</a> to have new videos summarized for you.
+			</p>
+		}
 		<div id="summary-list">
-			@summaryList(b, hasConnected)
+			@summaryList(b, hasConnected, autoSummarize)
 		</div>
 	}
 }
@@ -203,12 +212,16 @@ templ filterForm(f Filter, channels []string) {
 // and a single disclosure holding the older un-summarized back-catalogue. Cards
 // reflow to a single column on mobile; an empty list shows a friendly first-run
 // state instead of a blank table.
-templ summaryList(b listBuckets, hasConnected bool) {
+templ summaryList(b listBuckets, hasConnected bool, autoSummarize bool) {
 	if b.empty() {
 		if hasConnected {
 			<div class="empty empty-connected">
 				<strong>Your account is connected</strong>
-				<span>Tapir is finding your subscriptions and fetching captions — summaries appear here gradually. Check back later.</span>
+				if autoSummarize {
+					<span>Tapir is finding your subscriptions and fetching captions — summaries appear here gradually. Check back later.</span>
+				} else {
+					<span>Tapir is finding your subscriptions. You are in Manual mode, so videos appear here with a Summarize button — pick the ones you want, or switch to Automatic in your account.</span>
+				}
 			</div>
 		} else {
 			<div class="empty">