feat(launcher): trim list rows to name+tags, scrollable detail panel

List rows showed the long `summary` (name+id+description fallback chain)
and overflowed. Now each row shows the module name with a small genre-
tags subline sourced from manifest.launcher.md (meta.tags, threaded onto
the entry in init). The list also scrolls properly now (wheel dispatch +
upper clamp) — it was wired but dead without a wheel binding.

Detail panel: description + dependency list ran off the bottom of the
window. The mid-section (title/description/deps) now scrolls inside a
begin_view/end_view scissor region between the fixed hero strip and the
fixed launch button; news view scrolls too. Both panels get an inline
scrollbar. Detail scroll resets on module switch.

Depends on engine.input.get_mouse_wheel (sporel-engine). README controls/
demonstrates synced.

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

init.lua

@@ -199,7 +199,10 @@ function init(ctx)
         module_entries     = {},       -- filled below from engine.module.list
         news_entry         = { title = nil, body_path = "news.md" },
         selected_entry     = nil,
-        scroll_y           = 0,
+        scroll_y           = 0,          -- list-panel vertical scroll
+        detail_scroll_y    = 0,          -- detail-panel content scroll
+        detail_content_h   = 0,          -- set by detail.render each frame
+        detail_view_h      = 0,          -- scrollable viewport height, set by detail.render
         list_tint          = nil,      -- nil | "warn" | "error" — set in L.4
         list_panel_rect    = nil,      -- set below from window size
         detail_panel_rect  = nil,
@@ -263,6 +266,7 @@ function init(ctx)
         local meta, blocks = manifest_loader.load_for(entry.id)
         ctx_panels.manifest_cache[entry.id] = { meta = meta, blocks = blocks }
         entry.summary = meta.summary
+        entry.tags = meta.tags   -- L-fix: list-row subline (genre tags)
 
         -- L.4: also surface manifest.module::deps[] verbatim so the
         -- detail-panel can render per-dep status glyphs in load order
@@ -392,6 +396,16 @@ function update(ctx, dt)
     end
 
     if state == STATE_LIST then
+        -- Mouse-wheel scroll: route to whichever panel the cursor is over.
+        local wheel = engine.input.get_mouse_wheel()
+        if wheel ~= 0 then
+            if hit(ctx_panels.detail_panel_rect, mx, my) then
+                detail_panel.handle_scroll(ctx_panels, wheel)
+            elseif hit(ctx_panels.list_panel_rect, mx, my) then
+                list_panel.handle_scroll(ctx_panels, wheel)
+            end
+        end
+
         if input.was_action_pressed("ui_back") then
             state = fsm.next(state, "esc")
         elseif input.was_action_pressed("ui_click") then