Pulse a hovered joker's combo partners on the board

While hovering a shop/pack joker (or an owned one), the owned jokers it
synergizes with juice gently every ~0.9s, so the tooltip's partner names
are matched to cards by eye. Partner set is computed once per hover and
dropped when it ends. New config toggle: partner_highlight (default on);
stays active in learning mode since it explains rather than judges.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

main.lua

@@ -318,6 +318,32 @@ end
 
 -- Shop pulse ------------------------------------------------------------------
 
+-- Partner highlight: while a joker is hovered, the owned jokers it combos
+-- with pulse gently so your eyes can find them on the board. The partner
+-- set is computed once per hover (scoring every frame would be wasteful)
+-- and dropped when the hover ends, so board changes are picked up.
+local function highlight_partners(card, dt)
+    if not (card.states and card.states.hover and card.states.hover.is) then
+        card.jca_hl = nil
+        return
+    end
+    if not card.jca_hl then
+        local set = {}
+        for _, p in ipairs(JCA.partners_for(card)) do set[p.key] = true end
+        card.jca_hl = {set = set, t = 99} -- oversized t: first pulse now
+    end
+    card.jca_hl.t = card.jca_hl.t + dt
+    if card.jca_hl.t >= 0.9 then
+        card.jca_hl.t = 0
+        for _, owned in ipairs(G.jokers and G.jokers.cards or {}) do
+            if owned ~= card and owned.config and owned.config.center
+                and card.jca_hl.set[owned.config.center.key] then
+                owned:juice_up(0.15, 0.08)
+            end
+        end
+    end
+end
+
 local orig_update = Card.update
 function Card:update(dt)
     orig_update(self, dt)
@@ -331,6 +357,11 @@ function Card:update(dt)
             if ok and rec then self:juice_up(0.25, 0.15) end
         end
     end
+    if JCA.config.partner_highlight and G.STAGE == G.STAGES.RUN
+        and is_joker(self)
+        and (in_buy_area(self) or self.area == G.jokers) then
+        pcall(highlight_partners, self, dt)
+    end
 end
 
 -- Combo discovery tracking -----------------------------------------------------
@@ -941,6 +972,12 @@ if SMODS.current_mod then
                     ref_table = JCA.config, ref_value = 'owned_tooltip',
                 },
             }},
+            {n = G.UIT.R, config = {align = 'cm', padding = 0.05}, nodes = {
+                create_toggle{
+                    label = 'Highlight combo partners on hover',
+                    ref_table = JCA.config, ref_value = 'partner_highlight',
+                },
+            }},
             {n = G.UIT.R, config = {align = 'cm', padding = 0.05}, nodes = {
                 create_toggle{
                     label = 'Learning mode (no verdicts, just reasons)',