feat(search): subscription-only search mode when YouTube search is disabled

When pages_enabled.search is false, instead of blocking search entirely,
the search bar now searches within the user's subscriptions and saved
playlists only. YouTube's search API is never called.

Changes:
- routes/search.cr: detect search_disabled, force subscription+playlist
  search for logged-in users, 403 for anonymous users
- search/processors.cr: new subscriptions_and_playlists() method that
  queries both the subscription materialized view and playlist_videos
  table, merges and deduplicates results
- before_all.cr: let /search through to the route handler (APIs still
  blocked), keep /hashtag/* blocked
- search_box.ecr: dynamic placeholder ("Search subscriptions & playlists")
- search_homepage.ecr: hint text when in subscription-only mode
- search.ecr: hide YouTube filters, show lock icon + notice, custom
  empty-results message
- template.ecr: always show search bar (subscription search needs it)
- en-US.json: 6 new locale strings for subscription-only search UX

locales/en-US.json

@@ -6,6 +6,12 @@
   "popular_page_disabled": "The Popular feed has been disabled by the administrator.",
   "trending_page_disabled": "The Trending feed has been disabled by the administrator.",
   "search_page_disabled": "The Search feature has been disabled by the administrator.",
+  "search_subscriptions_placeholder": "Search subscriptions & playlists...",
+  "search_subscriptions_hint": "YouTube search is disabled. Search within your subscriptions and playlists.",
+  "search_subscriptions_login_required": "Please log in to search your subscriptions and playlists.",
+  "search_subscriptions_mode_notice": "Searching within your subscriptions and playlists only.",
+  "search_subscriptions_no_results": "No results found in your subscriptions or playlists.",
+  "search_subscriptions_no_results_hint": "Try a different search term, or make sure the channel is in your subscriptions.",
   "generic_channels_count": "{{count}} channel",
   "generic_channels_count_plural": "{{count}} channels",
   "generic_views_count": "{{count}} view",

src/invidious/routes/before_all.cr

@@ -150,9 +150,14 @@ module Invidious::Routes::BeforeAll
                  "popular"
                when "/feed/trending", "/api/v1/trending"
                  "trending"
-               when "/search", "/api/v1/search", "/api/v1/search/suggestions", "/results"
+               when "/api/v1/search", "/api/v1/search/suggestions"
                  "search"
-               when .starts_with?("/hashtag/"), .starts_with?("/api/v1/hashtag/")
+               when .starts_with?("/api/v1/hashtag/")
+                 "search"
+               when "/search", "/results"
+                 # Handled by the search route (subscription-only mode when search disabled)
+                 nil
+               when .starts_with?("/hashtag/")
                  "search"
                else
                  nil

src/invidious/routes/search.cr

@@ -40,6 +40,8 @@ module Invidious::Routes::Search
     preferences = env.get("preferences").as(Preferences)
     locale = preferences.locale
 
+    search_disabled = !CONFIG.page_enabled?("search")
+
     region = env.params.query["region"]? || preferences.region
 
     query = Invidious::Search::Query.new(env.params.query, :regular, region)
@@ -50,6 +52,35 @@ module Invidious::Routes::Search
       return templated "search_homepage", navbar_search: false
     end
 
+    # When YouTube search is disabled, force subscription-only mode
+    if search_disabled
+      user = env.get?("user")
+      if !user
+        return error_template(403, translate(locale, "search_subscriptions_login_required"))
+      end
+
+      user = user.as(User)
+
+      begin
+        items = Invidious::Search::Processors.subscriptions_and_playlists(query, user)
+      rescue ex
+        return error_template 500, ex
+      end
+
+      redirect_url = Invidious::Frontend::Misc.redirect_url(env)
+
+      page_nav_html = Frontend::Pagination.nav_numeric(locale,
+        base_url: "/search?#{query.to_http_params}",
+        current_page: query.page,
+        show_next: (items.size >= 20)
+      )
+
+      env.set "search", query.text
+      env.set "subscription_only_search", true
+
+      return templated "search"
+    end
+
     # non‐empty query → process it
     user = env.get?("user")
     if query.url?
@@ -59,7 +90,7 @@ module Invidious::Routes::Search
     begin
       items = user ? query.process(user.as(User)) : query.process
     rescue ex : ChannelSearchException
-      return error_template 404, "Unable to find channel with id “#{HTML.escape(ex.channel)}”…"
+      return error_template 404, "Unable to find channel with id "#{HTML.escape(ex.channel)}"…"
     rescue ex
       return error_template 500, ex
     end

src/invidious/search/processors.cr

@@ -52,5 +52,57 @@ module Invidious::Search
         as: ChannelVideo
       )
     end
+
+    # Search subscriptions AND saved playlists (used when YouTube search is disabled)
+    def subscriptions_and_playlists(query : Query, user : Invidious::User) : Array(ChannelVideo)
+      view_name = "subscriptions_#{sha256(user.email)}"
+      offset = (query.page - 1) * 20
+
+      # Search subscription videos via the materialized view
+      sub_results = PG_DB.query_all("
+        SELECT id, title, published, updated, ucid, author, length_seconds
+        FROM (
+          SELECT *,
+          to_tsvector(#{view_name}.title) ||
+          to_tsvector(#{view_name}.author)
+          as document
+          FROM #{view_name}
+        ) v_search WHERE v_search.document @@ plainto_tsquery($1)
+        ORDER BY published DESC
+        LIMIT 20 OFFSET $2;",
+        query.text, offset,
+        as: ChannelVideo
+      )
+
+      # Search playlist videos from user's playlists (both created and saved)
+      playlist_results = PG_DB.query_all("
+        SELECT pv.id, pv.title, pv.published, pv.published AS updated,
+               pv.ucid, pv.author, pv.length_seconds
+        FROM playlist_videos pv
+        INNER JOIN playlists p ON p.id = pv.plid
+        WHERE p.author = $1
+          AND (to_tsvector(pv.title) || to_tsvector(pv.author)) @@ plainto_tsquery($2)
+        ORDER BY pv.published DESC
+        LIMIT 20 OFFSET $3;",
+        user.email, query.text, offset,
+        as: ChannelVideo
+      )
+
+      # Merge, deduplicate by video ID, sort by published date, limit to 20
+      seen = Set(String).new
+      combined = [] of ChannelVideo
+
+      (sub_results + playlist_results)
+        .sort_by { |v| v.published }
+        .reverse!
+        .each do |video|
+          next if seen.includes?(video.id)
+          seen.add(video.id)
+          combined << video
+          break if combined.size >= 20
+        end
+
+      return combined
+    end
   end
 end

src/invidious/views/components/search_box.ecr

@@ -1,12 +1,13 @@
 <form class="pure-form" action="/search" method="get">
 	<fieldset>
+		<% search_placeholder = CONFIG.page_enabled?("search") ? translate(locale, "search") : translate(locale, "search_subscriptions_placeholder") %>
 		<input type="search" id="searchbox" autocorrect="off"
 		autocapitalize="none" spellcheck="false" <% if autofocus %>autofocus<% end %>
-		name="q" placeholder="<%= translate(locale, "search") %>"
+		name="q" placeholder="<%= search_placeholder %>"
-		title="<%= translate(locale, "search") %>"
+		title="<%= search_placeholder %>"
 		value="<%= env.get?("search").try {|x| HTML.escape(x.as(String)) } %>">
 	</fieldset>
-	<button type="submit" id="searchbutton" aria-label="<%= translate(locale, "search") %>">
+	<button type="submit" id="searchbutton" aria-label="<%= search_placeholder %>">
 		<i class="icon ion-ios-search"></i>
 	</button>
 </form>

src/invidious/views/search.ecr

@@ -3,17 +3,31 @@
 <link rel="stylesheet" href="/css/search.css?v=<%= ASSET_COMMIT %>">
 <% end %>
 
+<% subscription_only = env.get?("subscription_only_search") %>
+
+<% if subscription_only %>
+<div class="h-box" style="margin-bottom: 0.5em;">
+    <p style="color: var(--text-color-muted, #888);"><i class="icon ion-ios-lock"></i> <%= translate(locale, "search_subscriptions_mode_notice") %></p>
+</div>
+<hr/>
+<% else %>
 <!-- Search redirection and filtering UI -->
 <%= Invidious::Frontend::SearchFilters.generate(query.filters, query.text, query.page, locale) %>
 <hr/>
+<% end %>
 
 
 <%- if items.empty? -%>
 <div class="h-box no-results-error">
     <div>
-        <%= translate(locale, "search_message_no_results") %><br/><br/>
+        <% if subscription_only %>
-        <%= translate(locale, "search_message_change_filters_or_query") %><br/><br/>
+            <%= translate(locale, "search_subscriptions_no_results") %><br/><br/>
-        <%= translate(locale, "search_message_use_another_instance", redirect_url) %>
+            <%= translate(locale, "search_subscriptions_no_results_hint") %>
+        <% else %>
+            <%= translate(locale, "search_message_no_results") %><br/><br/>
+            <%= translate(locale, "search_message_change_filters_or_query") %><br/><br/>
+            <%= translate(locale, "search_message_use_another_instance", redirect_url) %>
+        <% end %>
     </div>
 </div>
 <%- else -%>

src/invidious/views/search_homepage.ecr

@@ -12,11 +12,14 @@
     <div class="pure-u-1" id="logo">
         <h1 href="/" class="pure-menu-heading">Invidious</h1>
     </div>
-    <% if CONFIG.page_enabled?("search") %>
     <div class="pure-u-1-4"></div>
     <div class="pure-u-1 pure-u-md-12-24 searchbar">
         <% autofocus = true %><%= rendered "components/search_box" %>
     </div>
     <div class="pure-u-1-4"></div>
+    <% if !CONFIG.page_enabled?("search") %>
+    <div class="pure-u-1" style="text-align: center; margin-top: 0.5em;">
+        <p style="color: var(--text-color-muted, #888);"><%= translate(locale, "search_subscriptions_hint") %></p>
+    </div>
     <% end %>
 </div>

src/invidious/views/template.ecr

@@ -31,17 +31,13 @@
     <div class="pure-g">
         <div class="pure-u-1 pure-u-xl-20-24" id="contents">
             <div class="pure-g navbar h-box">
-                <% if navbar_search && CONFIG.page_enabled?("search") %>
+                <% if navbar_search %>
                     <div class="pure-u-1 pure-u-md-4-24">
                         <a href="/" class="index-link pure-menu-heading">Invidious</a>
                     </div>
                     <div class="pure-u-1 pure-u-md-12-24 searchbar">
                         <% autofocus = false %><%= rendered "components/search_box" %>
                     </div>
-                <% elsif navbar_search %>
-                    <div class="pure-u-1 pure-u-md-16-24">
-                        <a href="/" class="index-link pure-menu-heading">Invidious</a>
-                    </div>
                 <% end %>
 
                 <div class="pure-u-1 pure-u-md-8-24 user-field">