Add theme-level discovery

A synergy theme counts as explored the first time two different
fielded jokers connect it (one gives the tag, one wants it; cluster
members carry both sides, so any two qualify). Explored themes
persist in config.themes_found, badge their catalog page with
"explored!", and feed a per-tab progress line. One toast per
emplacement, with famous pairs outranking themes.

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

main.lua

@@ -18,8 +18,10 @@ JCA.db = data.jokers
 -- Fallback defaults keep the engine usable outside the game (tests).
 JCA.mod = SMODS.current_mod
 JCA.config = SMODS.current_mod and SMODS.current_mod.config
-    or { pulse = true, owned_tooltip = true, threshold = 4, discovered = {} }
+    or { pulse = true, owned_tooltip = true, threshold = 4,
+         discovered = {}, themes_found = {} }
 JCA.config.discovered = JCA.config.discovered or {}
+JCA.config.themes_found = JCA.config.themes_found or {}
 
 -- Explicit famous pairs, stored under a canonical "a|b" key (a < b).
 JCA.pair_list = data.pairs
@@ -315,8 +317,43 @@ function JCA.check_discoveries()
             end
         end
     end
+    -- Theme discovery: a theme is explored once two DIFFERENT fielded jokers
+    -- connect it — one gives the tag, another wants it (cluster members do
+    -- both, so any two of them qualify).
+    local new_theme
+    for tag in pairs(data.theme_info or {}) do
+        if not JCA.config.themes_found[tag] then
+            local giver, wanter
+            for idx, k in ipairs(keys) do
+                local e = JCA.db[k]
+                if e then
+                    if e.gives[tag] and not giver then giver = idx end
+                    if e.wants[tag] and not wanter then wanter = idx end
+                end
+            end
+            if giver and wanter and giver == wanter then
+                wanter = nil -- same joker on both sides: find a second one
+                for idx, k in ipairs(keys) do
+                    local e = JCA.db[k]
+                    if e and idx ~= giver and (e.gives[tag] or e.wants[tag]) then
+                        wanter = idx
+                        break
+                    end
+                end
+            end
+            if giver and wanter then
+                JCA.config.themes_found[tag] = true
+                new_theme = new_theme or tag
+            end
+        end
+    end
+
+    if (new_pair or new_theme) and JCA.mod and SMODS.save_mod_config then
+        SMODS.save_mod_config(JCA.mod)
+    end
+    -- One toast per emplacement; a famous pair outranks a theme (both stay
+    -- recorded either way).
     if new_pair then
-        if JCA.mod and SMODS.save_mod_config then SMODS.save_mod_config(JCA.mod) end
         pcall(function()
             attention_text({
                 text = 'New combo: ' .. new_pair .. '!',
@@ -326,6 +363,18 @@ function JCA.check_discoveries()
             })
             play_sound('card1', 1.1, 0.6)
         end)
+    elseif new_theme then
+        pcall(function()
+            attention_text({
+                text = 'Theme explored: '
+                    .. ((JCA.theme_names and JCA.theme_names[new_theme]) or new_theme)
+                    .. '!',
+                scale = 0.7, hold = 4, major = G.play, align = 'cm',
+                offset = {x = 0, y = -3.5}, silent = true,
+                backdrop_colour = G.C.SECONDARY_SET.Planet,
+            })
+            play_sound('card1', 1.1, 0.6)
+        end)
     end
 end
 
@@ -463,6 +512,13 @@ local THEME_TABS = {
     }},
 }
 
+-- Display names for theme tags (used by the discovery toast, which runs
+-- before this point in the file but only ever fires during gameplay).
+JCA.theme_names = {}
+for _, group in ipairs(THEME_TABS) do
+    for _, t in ipairs(group.themes) do JCA.theme_names[t.tag] = t.name end
+end
+
 -- Joker keys for a tag, split into pure sources (give only), pure payoffs
 -- (want only), and cluster members (both). Sorted by display name.
 local function theme_members(tag)
@@ -625,10 +681,18 @@ local function theme_tab_def(group, page_no)
     if #both > 0 then groups[#groups + 1] = both end
     if #sources > 0 then groups[#groups + 1] = sources; captions = captions + 1 end
     if #payoffs > 0 then groups[#groups + 1] = payoffs; captions = captions + 1 end
-    local layout = pick_layout(groups, 1 + #blurb_lines + captions)
+    -- +2 text rows: the title and the group progress line above the pager
+    local layout = pick_layout(groups, 2 + #blurb_lines + captions)
 
     local nodes = {}
-    add_caption(nodes, theme.name)
+    if JCA.config.themes_found[theme.tag] then
+        nodes[#nodes + 1] = {n = G.UIT.R, config = {align = 'cm', padding = 0.02}, nodes = {
+            {n = G.UIT.T, config = {text = theme.name, colour = G.C.GOLD, scale = 0.3}},
+            {n = G.UIT.T, config = {text = '  explored!', colour = G.C.GREEN, scale = 0.3}},
+        }}
+    else
+        add_caption(nodes, theme.name)
+    end
     add_info_rows(nodes, data.theme_info[theme.tag], 70, 0.26)
     if #both > 0 then
         add_card_rows(nodes, both, layout.scale, layout.per_row)
@@ -641,6 +705,16 @@ local function theme_tab_def(group, page_no)
         add_caption(nodes, 'Payoffs - these want it')
         add_card_rows(nodes, payoffs, layout.scale, layout.per_row)
     end
+    local explored = 0
+    for _, t in ipairs(group.themes) do
+        if JCA.config.themes_found[t.tag] then explored = explored + 1 end
+    end
+    nodes[#nodes + 1] = {n = G.UIT.R, config = {align = 'cm', padding = 0.02}, nodes = {
+        {n = G.UIT.T, config = {
+            text = ('%d of %d themes explored - field a source and a payoff together')
+                :format(explored, #group.themes),
+            colour = G.C.UI.TEXT_LIGHT, scale = 0.24}},
+    }}
     local options = {}
     for i, t in ipairs(group.themes) do options[i] = t.name end
     nodes[#nodes + 1] = pager_row(options, page_no, 'jca_page_' .. group.label)