fix(launcher): wire FSM dispatch + correct conflict-count

The conflict-modal path bypassed the FSM extension landed in L.7:
panels/detail.lua set ctx.modal_open directly and init.lua drove
modal handling off the side-channel field, so STATE_MODAL_CONFLICT
was unreachable at runtime (only the test-lib asserts exercised it).
Now detail.lua marks ctx._pending_modal_open and init.lua dispatches
the open_conflict event so state actually transitions through the
fsm. Modal entry/exit is gated on state == STATE_MODAL_CONFLICT.

Also fixes the conflict body line: r.missing doesn't exist on the
dep-fetcher result; use #(errors) + #(conflicts) for the count
displayed in the modal body.

panels/detail.lua

@@ -155,7 +155,7 @@ function M.handle_click(ctx, mx, my)
                 body = {
                     ctx.t("conflict_body_line1"),
                     string.format(ctx.t("conflict_body_line2_fmt"),
-                                  r and #r.missing or 0),
+                                  r and (#(r.errors or {}) + #(r.conflicts or {})) or 0),
                 },
                 buttons = {
                     { id = "cancel",        label = ctx.t("cancel") },
@@ -164,7 +164,9 @@ function M.handle_click(ctx, mx, my)
                 },
                 module_id = entry.id,
             }
-            ctx.modal_open = "conflict"
+            -- C1: signal init.lua to dispatch open_conflict on the FSM
+            -- so state actually transitions into STATE_MODAL_CONFLICT.
+            ctx._pending_modal_open = "conflict"
         end
         return true
     end