feat(launcher): hero carousel with auto-rotate + manual nav

panels/carousel.lua holds per-module state (index, timer, manual pause,
texture cache). Auto-rotate at carousel_interval_seconds (5s default,
frontmatter-overrideable). Click on overlay arrows steps and pauses
auto-rotate for 30s. Max 7 indicator dots, then 'X / N' overlay (L-Q4).
Single-teaser hides the arrows and dots. Zero-teaser falls through to
ctx.default_teaser_texture which L.10 ships.

panels/detail.lua

@@ -58,10 +58,13 @@ function M.render(ctx)
     if not entry then return end
     local mc = ctx.manifest_cache[entry.id] or { meta = {}, blocks = {} }
 
-    -- Carousel hero placeholder: L.5 swaps this in. For now: a strip.
+    -- Hero carousel (L.5). Renders bg + texture + arrows + dots.
+    -- Zero-teaser modules render the default_teaser_texture (L.10)
+    -- on top of the COLOR_FALLBACK_BG strip.
     local hero_h = 160
-    if ctx.carousel_state[entry.id] and ctx.carousel_mod then
-        -- L.5 implements this; render call lands later.
+    local s = ctx.carousel_state[entry.id]
+    if s and ctx.carousel_mod then
+        ctx.carousel_mod.render(s, p.x, p.y, p.w, hero_h, ctx.default_teaser_texture)
     else
         engine.render.draw_rect(p.x, p.y, p.w, hero_h, 0x404040FF)
     end
@@ -115,7 +118,16 @@ function M.render(ctx)
 end
 
 function M.handle_click(ctx, mx, my)
-    -- L.5/L.7 add carousel-arrow + launch-button hit-tests.
+    -- L.5: carousel arrow hit-test. L.7 will add launch-button.
+    if not ctx.selected_entry or ctx.selected_entry == "news" then
+        return false
+    end
+    local entry = find_entry(ctx, ctx.selected_entry)
+    if not entry then return false end
+    local s = ctx.carousel_state[entry.id]
+    if s and ctx.carousel_mod and ctx.carousel_mod.handle_click(s, mx, my) then
+        return true
+    end
     return false
 end