finished main-menu so far

Assets/Data/Cards/CardDatabase.asset

@@ -29,3 +29,9 @@ MonoBehaviour:
   - {fileID: 11400000, guid: c1a50000000000000000000000000003, type: 2}
   - {fileID: 11400000, guid: c1a50000000000000000000000000004, type: 2}
   - {fileID: 11400000, guid: c1a50000000000000000000000000005, type: 2}
+  - {fileID: 11400000, guid: a7d40000000000000000000000000001, type: 2}
+  - {fileID: 11400000, guid: a7d40000000000000000000000000002, type: 2}
+  - {fileID: 11400000, guid: a7d40000000000000000000000000003, type: 2}
+  - {fileID: 11400000, guid: a7d40000000000000000000000000004, type: 2}
+  - {fileID: 11400000, guid: a7d40000000000000000000000000005, type: 2}
+  - {fileID: 11400000, guid: a7d40000000000000000000000000006, type: 2}

Assets/Scenes/MainMenuScene.unity

@@ -307,4 +307,5 @@ MonoBehaviour:
   motdBody: unstable userspace detected; keep a rollback shell open.
   distroDatabase: {fileID: 11400000, guid: 4d88ca5446fa4d80b2fbd4b12697cb7c, type: 2}
   cardDatabase: {fileID: 11400000, guid: 6a8a9f37c98a4a7a9e67ab15d2d22208, type: 2}
+  languageDeckDatabase: {fileID: 11400000, guid: a7d20000000000000000000000000001, type: 2}
   featuredUnitPanel: {}

Assets/Scripts/Data/CardDefinition.cs

@@ -20,6 +20,7 @@ namespace KernelPanic.Data
         [SerializeField] private bool distroExclusive;
         [SerializeField] private bool isToken;
         [SerializeField, TextArea] private string designNotes;
+        [SerializeField] private List<string> requiresSystem = new();
         [SerializeField] private CardDefinition upgradeTarget;
         [SerializeField] private List<CardEffectDefinition> effects = new();
 
@@ -34,6 +35,7 @@ namespace KernelPanic.Data
         public bool DistroExclusive => distroExclusive;
         public bool IsToken => isToken;
         public string DesignNotes => designNotes;
+        public IReadOnlyList<string> RequiresSystem => requiresSystem;
         public CardDefinition UpgradeTarget => upgradeTarget;
         public IReadOnlyList<CardEffectDefinition> Effects => effects;
     }

Assets/Scripts/UI/CollectionScreenController.cs

@@ -1,6 +1,8 @@
 using System;
 using System.Collections.Generic;
+using KernelPanic.Core;
 using KernelPanic.Data;
+using KernelPanic.Meta;
 using UnityEngine;
 using UnityEngine.TextCore.Text;
 using UnityEngine.UIElements;
@@ -8,7 +10,7 @@ using UnityEngine.UIElements;
 namespace KernelPanic.UI
 {
     /// <summary>
-    /// Renders the owned-units list and detail readout on the collection screen.
+    /// Renders Collection tabs and the pushed read-only card subview.
     /// </summary>
     [Serializable]
     public sealed class CollectionScreenController
@@ -18,20 +20,116 @@ namespace KernelPanic.UI
         private VisualElement list;
         private VisualElement detail;
         private FontAsset monospaceFont;
+        private LanguageDeckDatabase languageDeckDatabase;
+        private CardDatabase cardDatabase;
+        private PlayerCollection playerCollection;
         private IReadOnlyList<DistroDefinition> units = Array.Empty<DistroDefinition>();
+        private IReadOnlyList<LanguageCatalogEntry> languages = LanguageCatalog.All;
         private IReadOnlyList<CardEntry> cards = Array.Empty<CardEntry>();
-        private int selectedIndex;
+        private CollectionMode mode;
+        private CollectionMode returnMode;
+        private int selectedUnitIndex;
+        private int selectedLanguageIndex;
+        private int selectedCardIndex;
+        private string emptyCardMessage = "no cards installed";
 
-        public void Bind(VisualElement root, FontAsset artFont)
+        public event Action ViewChanged;
+
+        public void Bind(VisualElement root, FontAsset artFont, LanguageDeckDatabase deckDatabase, CardDatabase cardsDatabase, PlayerCollection collection)
         {
             monospaceFont = artFont;
+            languageDeckDatabase = deckDatabase;
+            cardDatabase = cardsDatabase;
+            playerCollection = collection;
             list = root.Q<VisualElement>("CollectionList");
             detail = root.Q<VisualElement>("CollectionDetail");
         }
 
+        public bool IsCardSubview => mode == CollectionMode.CardSubview;
+
+        public string CurrentTitle { get; private set; } = "$ ls ~/collection";
+        public string CurrentHint { get; private set; } = "[esc] back   [left/right] tabs   [tab] tabs   [arrows] navigate   [enter] select";
+
         public void RefreshUnits(IReadOnlyList<DistroDefinition> ownedUnits)
         {
             units = ownedUnits ?? Array.Empty<DistroDefinition>();
+            ShowUnits();
+        }
+
+        public void ShowUnits()
+        {
+            mode = CollectionMode.Units;
+            CurrentTitle = "$ ls ~/collection";
+            CurrentHint = "[esc] back   [left/right] tabs   [tab] tabs   [arrows] navigate   [enter] select";
+            RenderUnits();
+            ViewChanged?.Invoke();
+        }
+
+        public void ShowLanguages()
+        {
+            mode = CollectionMode.Languages;
+            CurrentTitle = "$ ls ~/collection/languages";
+            CurrentHint = "[esc] back   [left/right] tabs   [tab] tabs   [arrows] navigate   [enter] select";
+            RenderLanguages();
+            ViewChanged?.Invoke();
+        }
+
+        public bool BackFromSubview()
+        {
+            if (!IsCardSubview)
+            {
+                return false;
+            }
+
+            if (returnMode == CollectionMode.Languages)
+            {
+                ShowLanguages();
+            }
+            else
+            {
+                ShowUnits();
+            }
+
+            return true;
+        }
+
+        public void SelectRelative(int delta)
+        {
+            if (mode == CollectionMode.Units)
+            {
+                SelectUnit(selectedUnitIndex + delta);
+                return;
+            }
+
+            if (mode == CollectionMode.Languages)
+            {
+                SelectLanguage(selectedLanguageIndex + delta);
+                return;
+            }
+
+            SelectCard(selectedCardIndex + delta);
+        }
+
+        public void ActivateSelected()
+        {
+            if (mode == CollectionMode.Units && units.Count > 0)
+            {
+                OpenUnitCards(units[selectedUnitIndex]);
+                return;
+            }
+
+            if (mode == CollectionMode.Languages && languages.Count > 0)
+            {
+                LanguageCatalogEntry language = languages[selectedLanguageIndex];
+                if (LanguageUnlock.IsUnlocked(language.Language, playerCollection))
+                {
+                    OpenLanguageDeck(language);
+                }
+            }
+        }
+
+        private void RenderUnits()
+        {
             if (list == null || detail == null)
             {
                 return;
@@ -48,7 +146,7 @@ namespace KernelPanic.UI
                 return;
             }
 
-            selectedIndex = Mathf.Clamp(selectedIndex, 0, units.Count - 1);
+            selectedUnitIndex = Mathf.Clamp(selectedUnitIndex, 0, units.Count - 1);
             for (int i = 0; i < units.Count; i++)
             {
                 int index = i;
@@ -62,21 +160,20 @@ namespace KernelPanic.UI
                 name.AddToClassList("collection-row-name");
                 name.style.color = new StyleColor(unit.AccentColor);
 
-                Label languages = new(DistroPresentation.FormatLanguages(unit));
+                Label unitLanguages = new(DistroPresentation.FormatLanguages(unit));
-                languages.AddToClassList("collection-row-languages");
+                unitLanguages.AddToClassList("collection-row-languages");
 
                 row.Add(name);
-                row.Add(languages);
+                row.Add(unitLanguages);
                 list.Add(row);
                 rows.Add(row);
             }
 
-            SelectUnit(selectedIndex);
+            SelectUnit(selectedUnitIndex);
         }
 
-        public void RefreshCards(DistroDefinition featuredUnit)
+        private void RenderLanguages()
         {
-            cards = BuildCardEntries(featuredUnit);
             if (list == null || detail == null)
             {
                 return;
@@ -84,43 +181,32 @@ namespace KernelPanic.UI
 
             rows.Clear();
             list.Clear();
+            selectedLanguageIndex = Mathf.Clamp(selectedLanguageIndex, 0, languages.Count - 1);
 
-            if (cards.Count == 0)
+            for (int i = 0; i < languages.Count; i++)
-            {
-                detail.Clear();
-                detail.Add(new Label("no cards installed") { name = "CollectionEmptyTitle" });
-                detail.Add(new Label("featured distro cards appear here") { name = "CollectionEmptyHint" });
-                return;
-            }
-
-            selectedIndex = Mathf.Clamp(selectedIndex, 0, cards.Count - 1);
-            for (int i = 0; i < cards.Count; i++)
             {
                 int index = i;
-                CardEntry entry = cards[i];
+                LanguageCatalogEntry language = languages[i];
+                bool unlocked = LanguageUnlock.IsUnlocked(language.Language, playerCollection);
                 VisualElement row = new();
                 row.AddToClassList("collection-row");
-                row.RegisterCallback<PointerEnterEvent>(_ => SelectCard(index));
+                row.EnableInClassList("locked", !unlocked);
-                row.RegisterCallback<ClickEvent>(_ => SelectCard(index));
+                row.RegisterCallback<PointerEnterEvent>(_ => SelectLanguage(index));
+                row.RegisterCallback<ClickEvent>(_ => SelectLanguage(index));
 
-                Label name = new(GetCardDisplayName(entry.Card));
+                Label name = new(unlocked ? language.DisplayName : $"{language.DisplayName} [locked]");
                 name.AddToClassList("collection-row-name");
 
-                Label meta = new($"{DistroPresentation.DisplayName(entry.Owner)} / {FormatCardMeta(entry.Card)}");
+                Label tag = new(language.IdentityTag);
-                meta.AddToClassList("collection-row-languages");
+                tag.AddToClassList("collection-row-languages");
 
                 row.Add(name);
-                row.Add(meta);
+                row.Add(tag);
                 list.Add(row);
                 rows.Add(row);
             }
 
-            SelectCard(selectedIndex);
+            SelectLanguage(selectedLanguageIndex);
-        }
-
-        public void Refresh(IReadOnlyList<DistroDefinition> ownedUnits)
-        {
-            RefreshUnits(ownedUnits);
         }
 
         private void SelectUnit(int index)
@@ -130,13 +216,16 @@ namespace KernelPanic.UI
                 return;
             }
 
-            selectedIndex = Mathf.Clamp(index, 0, units.Count - 1);
+            selectedUnitIndex = Mathf.Clamp(index, 0, units.Count - 1);
-            for (int i = 0; i < rows.Count; i++)
+            ApplySelection(selectedUnitIndex);
-            {
+            RenderUnitDetail(units[selectedUnitIndex]);
-                rows[i].EnableInClassList("selected", i == selectedIndex);
+        }
-            }
 
-            RenderDetail(units[selectedIndex]);
+        private void SelectLanguage(int index)
+        {
+            selectedLanguageIndex = Mathf.Clamp(index, 0, languages.Count - 1);
+            ApplySelection(selectedLanguageIndex);
+            RenderLanguageDetail(languages[selectedLanguageIndex]);
         }
 
         private void SelectCard(int index)
@@ -146,16 +235,20 @@ namespace KernelPanic.UI
                 return;
             }
 
-            selectedIndex = Mathf.Clamp(index, 0, cards.Count - 1);
+            selectedCardIndex = Mathf.Clamp(index, 0, cards.Count - 1);
+            ApplySelection(selectedCardIndex);
+            RenderCardDetail(cards[selectedCardIndex]);
+        }
+
+        private void ApplySelection(int selectedIndex)
+        {
             for (int i = 0; i < rows.Count; i++)
             {
                 rows[i].EnableInClassList("selected", i == selectedIndex);
             }
-
-            RenderCardDetail(cards[selectedIndex]);
         }
 
-        private void RenderDetail(DistroDefinition unit)
+        private void RenderUnitDetail(DistroDefinition unit)
         {
             detail.Clear();
 
@@ -182,7 +275,6 @@ namespace KernelPanic.UI
 
             VisualElement details = new();
             details.AddToClassList("collection-detail-values");
-
             details.Add(BuildDetailLine("lang", DistroPresentation.FormatLanguages(unit)));
             details.Add(BuildDetailLine("uptime", unit.BaseUptime.ToString()));
             details.Add(BuildDetailLine("ram", unit.BaseRam.ToString()));
@@ -190,6 +282,118 @@ namespace KernelPanic.UI
 
             readout.Add(details);
             detail.Add(readout);
+            detail.Add(BuildSubviewCommand($"> cat ~/units/{unit.Id}/cards", "exclusive packages", HasListableCards(unit), () => OpenUnitCards(unit), "no packages installed"));
+        }
+
+        private void RenderLanguageDetail(LanguageCatalogEntry language)
+        {
+            detail.Clear();
+            bool unlocked = LanguageUnlock.IsUnlocked(language.Language, playerCollection);
+
+            Label name = new(language.DisplayName);
+            name.AddToClassList("collection-detail-name");
+            detail.Add(name);
+            detail.Add(BuildDetailLine("track", language.ResolutionTrack.ToString()));
+
+            Label how = new(language.HowItWorks);
+            how.AddToClassList("collection-detail-description");
+            detail.Add(how);
+
+            if (!unlocked)
+            {
+                string hintText = string.IsNullOrWhiteSpace(language.UnlockHint)
+                    ? $"unlock: own a distro that speaks {language.DisplayName} ({FormatSupportingDistros(language)})"
+                    : language.UnlockHint;
+                Label hint = new(hintText);
+                hint.AddToClassList("package-notice");
+                detail.Add(hint);
+                return;
+            }
+
+            detail.Add(BuildSubviewCommand($"> cat ~/lang/{GetLanguageId(language.Language)}/deck", "starter deck", true, () => OpenLanguageDeck(language), null));
+        }
+
+        private void OpenUnitCards(DistroDefinition unit)
+        {
+            if (!HasListableCards(unit))
+            {
+                return;
+            }
+
+            returnMode = CollectionMode.Units;
+            cards = BuildUnitCardEntries(unit);
+            emptyCardMessage = "no packages installed";
+            CurrentTitle = $"$ cat ~/units/{unit.Id}/cards";
+            CurrentHint = "[esc] back   [arrows] navigate";
+            RenderCardSubview();
+            ViewChanged?.Invoke();
+        }
+
+        private void OpenLanguageDeck(LanguageCatalogEntry language)
+        {
+            returnMode = CollectionMode.Languages;
+            cards = BuildStarterDeckEntries(language);
+            emptyCardMessage = "starter deck not yet available";
+            CurrentTitle = $"$ cat ~/lang/{GetLanguageId(language.Language)}/deck";
+            CurrentHint = "[esc] back   [arrows] navigate";
+            RenderCardSubview();
+            ViewChanged?.Invoke();
+        }
+
+        private void RenderCardSubview()
+        {
+            mode = CollectionMode.CardSubview;
+            rows.Clear();
+            list.Clear();
+            detail.Clear();
+            selectedCardIndex = Mathf.Clamp(selectedCardIndex, 0, Math.Max(0, cards.Count - 1));
+
+            if (cards.Count == 0)
+            {
+                detail.Add(new Label(emptyCardMessage) { name = "CollectionEmptyTitle" });
+                detail.Add(new Label("check back after deck data is installed") { name = "CollectionEmptyHint" });
+                return;
+            }
+
+            for (int i = 0; i < cards.Count; i++)
+            {
+                int index = i;
+                CardEntry entry = cards[i];
+                VisualElement row = BuildCardRow(entry);
+                row.RegisterCallback<PointerEnterEvent>(_ => SelectCard(index));
+                row.RegisterCallback<ClickEvent>(_ => SelectCard(index));
+                list.Add(row);
+                rows.Add(row);
+            }
+
+            SelectCard(selectedCardIndex);
+        }
+
+        private VisualElement BuildCardRow(CardEntry entry)
+        {
+            VisualElement row = new();
+            row.AddToClassList("package-row");
+            row.AddToClassList("collection-card-row");
+
+            VisualElement summary = new();
+            summary.AddToClassList("package-summary");
+
+            Label count = new(entry.Count > 1 ? $"x{entry.Count}" : string.Empty);
+            count.AddToClassList("package-marker");
+            Label name = new(GetCardDisplayName(entry.Card));
+            name.AddToClassList("package-name");
+            Label meta = new(FormatCardMeta(entry.Card));
+            meta.AddToClassList("package-meta");
+
+            summary.Add(count);
+            summary.Add(name);
+            summary.Add(meta);
+            row.Add(summary);
+
+            Label description = new(entry.Card == null || string.IsNullOrWhiteSpace(entry.Card.Description) ? "--" : entry.Card.Description);
+            description.AddToClassList("package-description");
+            row.Add(description);
+            return row;
         }
 
         private void RenderCardDetail(CardEntry entry)
@@ -204,6 +408,7 @@ namespace KernelPanic.UI
             Label description = new(card == null || string.IsNullOrWhiteSpace(card.Description) ? "--" : card.Description);
             description.AddToClassList("collection-detail-description");
             detail.Add(description);
+
             if (card != null && !string.IsNullOrWhiteSpace(card.FlavorText))
             {
                 Label flavor = new(card.FlavorText);
@@ -211,11 +416,10 @@ namespace KernelPanic.UI
                 detail.Add(flavor);
             }
 
-            detail.Add(BuildDetailLine("owner", DistroPresentation.DisplayName(entry.Owner)));
             detail.Add(BuildDetailLine("lang", card == null ? "--" : card.Language.ToString()));
             detail.Add(BuildDetailLine("rarity", card == null ? "--" : card.Rarity.ToString()));
             detail.Add(BuildDetailLine("cost", card == null ? "--" : card.CycleCost.ToString()));
-            detail.Add(BuildDetailLine("type", card != null && card.IsToken ? "token" : "loadout"));
+            detail.Add(BuildDetailLine("track", card == null ? "--" : card.ResolutionTrack.ToString()));
         }
 
         private static VisualElement BuildDetailLine(string key, string value)
@@ -233,6 +437,32 @@ namespace KernelPanic.UI
             return row;
         }
 
+        private VisualElement BuildSubviewCommand(string command, string description, bool enabled, Action action, string disabledDescription)
+        {
+            VisualElement row = new();
+            row.AddToClassList("command-row");
+            row.AddToClassList("collection-command-row");
+            row.EnableInClassList("disabled-row", !enabled);
+
+            Label cursor = new(">");
+            cursor.AddToClassList("command-cursor");
+            Label commandLabel = new(command);
+            commandLabel.AddToClassList("command-text");
+            Label descriptionLabel = new(enabled ? description : disabledDescription);
+            descriptionLabel.AddToClassList("command-description");
+
+            row.Add(cursor);
+            row.Add(commandLabel);
+            row.Add(descriptionLabel);
+
+            if (enabled)
+            {
+                row.RegisterCallback<ClickEvent>(_ => action?.Invoke());
+            }
+
+            return row;
+        }
+
         private static void AddPassiveDetails(VisualElement target, DistroDefinition unit)
         {
             if (unit.Passive == null)
@@ -256,28 +486,105 @@ namespace KernelPanic.UI
             }
         }
 
-        private static IReadOnlyList<CardEntry> BuildCardEntries(DistroDefinition featuredUnit)
+        private static IReadOnlyList<CardEntry> BuildUnitCardEntries(DistroDefinition unit)
         {
             List<CardEntry> entries = new();
-            if (featuredUnit == null)
+            if (unit == null)
             {
                 return entries;
             }
 
-            for (int cardIndex = 0; cardIndex < featuredUnit.ExclusiveCards.Count; cardIndex++)
+            for (int cardIndex = 0; cardIndex < unit.ExclusiveCards.Count; cardIndex++)
             {
-                CardDefinition card = featuredUnit.ExclusiveCards[cardIndex];
+                CardDefinition card = unit.ExclusiveCards[cardIndex];
+                if (card == null || card.IsToken)
+                {
+                    continue;
+                }
+
+                entries.Add(new CardEntry(unit, card, 1));
+            }
+
+            return entries;
+        }
+
+        private IReadOnlyList<CardEntry> BuildStarterDeckEntries(LanguageCatalogEntry language)
+        {
+            LanguageDeckDefinition deck = languageDeckDatabase == null ? null : languageDeckDatabase.FindByLanguage(language.Language);
+            if (deck == null)
+            {
+                return BuildRegisteredStarterDeckEntries(language.Language);
+            }
+
+            List<CardEntry> entries = new();
+            for (int i = 0; i < deck.Entries.Count; i++)
+            {
+                LanguageDeckDefinition.LanguageDeckEntry deckEntry = deck.Entries[i];
+                if (deckEntry.Card == null || deckEntry.Count <= 0)
+                {
+                    continue;
+                }
+
+                entries.Add(new CardEntry(null, deckEntry.Card, deckEntry.Count));
+            }
+
+            return entries;
+        }
+
+        private IReadOnlyList<CardEntry> BuildRegisteredStarterDeckEntries(Language language)
+        {
+            if (cardDatabase == null)
+            {
+                return Array.Empty<CardEntry>();
+            }
+
+            return language switch
+            {
+                Language.Python => BuildRegisteredStarterDeckEntries(
+                    ("lang_py_print", 2),
+                    ("lang_py_import_antigravity", 1),
+                    ("lang_py_for_loop", 1)),
+                Language.JavaScript => BuildRegisteredStarterDeckEntries(
+                    ("lang_js_console_log", 2),
+                    ("lang_js_fetch", 1),
+                    ("lang_js_typeof", 1)),
+                _ => Array.Empty<CardEntry>()
+            };
+        }
+
+        private IReadOnlyList<CardEntry> BuildRegisteredStarterDeckEntries(params (string Id, int Count)[] cardRefs)
+        {
+            List<CardEntry> entries = new();
+            for (int i = 0; i < cardRefs.Length; i++)
+            {
+                CardDefinition card = cardDatabase.FindById(cardRefs[i].Id);
                 if (card == null)
                 {
                     continue;
                 }
 
-                entries.Add(new CardEntry(featuredUnit, card));
+                entries.Add(new CardEntry(null, card, cardRefs[i].Count));
             }
 
             return entries;
         }
 
+        private static bool HasListableCards(DistroDefinition unit)
+        {
+            return BuildUnitCardEntries(unit).Count > 0;
+        }
+
+        private string FormatSupportingDistros(LanguageCatalogEntry language)
+        {
+            List<string> names = new();
+            for (int i = 0; i < language.SupportingDistros.Count; i++)
+            {
+                names.Add(language.SupportingDistros[i].DisplayName);
+            }
+
+            return string.Join(", ", names);
+        }
+
         private static string GetCardDisplayName(CardDefinition card)
         {
             if (card == null)
@@ -293,16 +600,36 @@ namespace KernelPanic.UI
             return card == null ? "--" : $"{card.Language} / {card.CycleCost}c";
         }
 
+        private static string GetLanguageId(Language language)
+        {
+            return language switch
+            {
+                Language.CPlusPlus => "cpp",
+                Language.JavaScript => "javascript",
+                Language.TypeScript => "typescript",
+                _ => language.ToString().ToLowerInvariant()
+            };
+        }
+
+        private enum CollectionMode
+        {
+            Units,
+            Languages,
+            CardSubview
+        }
+
         private readonly struct CardEntry
         {
-            public CardEntry(DistroDefinition owner, CardDefinition card)
+            public CardEntry(DistroDefinition owner, CardDefinition card, int count)
             {
                 Owner = owner;
                 Card = card;
+                Count = count;
             }
 
             public DistroDefinition Owner { get; }
             public CardDefinition Card { get; }
+            public int Count { get; }
         }
     }
 }

Assets/Scripts/UI/MainMenuController.cs

@@ -38,6 +38,7 @@ namespace KernelPanic.UI
         [SerializeField] private string motdBody = "unstable userspace detected; keep a rollback shell open.";
         [SerializeField] private DistroDatabase distroDatabase;
         [SerializeField] private CardDatabase cardDatabase;
+        [SerializeField] private LanguageDeckDatabase languageDeckDatabase;
         [SerializeField] private FeaturedUnitPanel featuredUnitPanel = new();
         [SerializeField] private CollectionScreenController collectionScreen = new();
         [SerializeField] private StarterSelectionController starterSelection = new();
@@ -45,6 +46,7 @@ namespace KernelPanic.UI
         private readonly List<CommandMenuEntry> commandEntries = new();
         private readonly List<VisualElement> packageRows = new();
         private readonly List<VisualElement> loadoutRows = new();
+        private readonly List<Language> selectedRunLanguages = new();
         private UIDocument document;
         private VisualElement root;
         private VisualElement shellRoot;
@@ -58,6 +60,7 @@ namespace KernelPanic.UI
         private VisualElement backgroundLogLayer;
         private ScrollView runSetupList;
         private VisualElement runSetupDetail;
+        private ScrollView runSetupPackageScroll;
         private Label appIdLabel;
         private Label entropyLabel;
         private Label pullTokensLabel;
@@ -67,7 +70,7 @@ namespace KernelPanic.UI
         private Label motdBodyLabel;
         private VisualElement motdBlock;
         private Button collectionUnitsButton;
-        private Button collectionCardsButton;
+        private Button collectionLanguagesButton;
         private readonly ScreenFrameController runSetupFrame = new();
         private readonly ScreenFrameController collectionFrame = new();
         private readonly ScreenFrameController gachaFrame = new();
@@ -83,7 +86,7 @@ namespace KernelPanic.UI
         private int selectedCommandIndex;
         private int selectedPackageIndex;
         private string runSetupNotice;
-        private bool collectionShowingCards;
+        private bool collectionShowingLanguages;
         private float bootIntroElapsed;
         private int bootIntroCharacterCount;
         private bool cursorVisible;
@@ -111,7 +114,7 @@ namespace KernelPanic.UI
             BindCommandEntries();
             RegisterCommandEntryCallbacks();
             featuredUnitPanel.Bind(root, monospaceFont);
-            collectionScreen.Bind(root, monospaceFont);
+            collectionScreen.Bind(root, monospaceFont, languageDeckDatabase, cardDatabase, playerCollection);
             BindScreenFrames();
             starterSelection.Bind(root, distroDatabase, HandleStarterConfirmed);
             LoadMetaState();
@@ -171,13 +174,13 @@ namespace KernelPanic.UI
             motdBodyLabel = root.Q<Label>("MotdBodyLabel");
 
             collectionUnitsButton = root.Q<Button>("CollectionUnitsButton");
-            collectionCardsButton = root.Q<Button>("CollectionCardsButton");
+            collectionLanguagesButton = root.Q<Button>("CollectionLanguagesButton");
         }
 
         private void BindScreenFrames()
         {
             runSetupFrame.Bind(runSetupPanel, "$ ./start_run --configure", "[esc] back   [arrows] navigate   [enter] select   [b] boot run", ShowMainMenu);
-            collectionFrame.Bind(collectionPanel, "$ ls ~/collection", "[esc] back   [left/right] tabs   [tab] tabs   [arrows] navigate   [enter] select", ShowMainMenu);
+            collectionFrame.Bind(collectionPanel, "$ ls ~/collection", "[esc] back   [left/right] tabs   [tab] tabs   [arrows] navigate   [enter] select", HandleCollectionBack);
             gachaFrame.Bind(gachaPanel, "$ curl gacha.sh | sh", "[esc] back", ShowMainMenu);
             settingsFrame.Bind(settingsPanel, "$ dpkg-reconfigure kernel-panic", "[esc] back", ShowMainMenu);
         }
@@ -206,16 +209,18 @@ namespace KernelPanic.UI
         {
             root.RegisterCallback<KeyDownEvent>(HandleKeyDown);
             root.RegisterCallback<PointerDownEvent>(HandlePointerDown);
+            collectionScreen.ViewChanged += SyncCollectionFrame;
             collectionUnitsButton.RegisterCallback<ClickEvent>(HandleCollectionUnitsTabClicked);
-            collectionCardsButton.RegisterCallback<ClickEvent>(HandleCollectionCardsTabClicked);
+            collectionLanguagesButton.RegisterCallback<ClickEvent>(HandleCollectionLanguagesTabClicked);
         }
 
         private void UnregisterCallbacks()
         {
             root.UnregisterCallback<KeyDownEvent>(HandleKeyDown);
             root.UnregisterCallback<PointerDownEvent>(HandlePointerDown);
+            collectionScreen.ViewChanged -= SyncCollectionFrame;
             collectionUnitsButton.UnregisterCallback<ClickEvent>(HandleCollectionUnitsTabClicked);
-            collectionCardsButton.UnregisterCallback<ClickEvent>(HandleCollectionCardsTabClicked);
+            collectionLanguagesButton.UnregisterCallback<ClickEvent>(HandleCollectionLanguagesTabClicked);
         }
 
         private void HandleCollectionUnitsTabClicked(ClickEvent evt)
@@ -224,9 +229,9 @@ namespace KernelPanic.UI
             evt.StopPropagation();
         }
 
-        private void HandleCollectionCardsTabClicked(ClickEvent evt)
+        private void HandleCollectionLanguagesTabClicked(ClickEvent evt)
         {
-            ShowCollectionCards();
+            ShowCollectionLanguages();
             evt.StopPropagation();
         }
 
@@ -468,6 +473,13 @@ namespace KernelPanic.UI
                 return;
             }
 
+            if (evt.keyCode == KeyCode.Escape && IsCollectionVisible() && collectionScreen.BackFromSubview())
+            {
+                SyncCollectionFrame();
+                evt.StopPropagation();
+                return;
+            }
+
             if (evt.keyCode == KeyCode.Escape && IsSubScreenVisible())
             {
                 ShowMainMenu();
@@ -501,12 +513,35 @@ namespace KernelPanic.UI
 
             if (IsCollectionVisible())
             {
-                if (evt.keyCode == KeyCode.LeftArrow || evt.keyCode == KeyCode.RightArrow || evt.keyCode == KeyCode.Tab)
+                if (!collectionScreen.IsCardSubview &&
+                    (evt.keyCode == KeyCode.LeftArrow || evt.keyCode == KeyCode.RightArrow || evt.keyCode == KeyCode.Tab))
                 {
                     ToggleCollectionTab();
                     evt.StopPropagation();
                     return;
                 }
+
+                if (evt.keyCode == KeyCode.UpArrow)
+                {
+                    collectionScreen.SelectRelative(-1);
+                    evt.StopPropagation();
+                    return;
+                }
+
+                if (evt.keyCode == KeyCode.DownArrow)
+                {
+                    collectionScreen.SelectRelative(1);
+                    evt.StopPropagation();
+                    return;
+                }
+
+                if (evt.keyCode == KeyCode.Return || evt.keyCode == KeyCode.KeypadEnter)
+                {
+                    collectionScreen.ActivateSelected();
+                    SyncCollectionFrame();
+                    evt.StopPropagation();
+                    return;
+                }
             }
 
             if (evt.keyCode == KeyCode.UpArrow)
@@ -568,6 +603,7 @@ namespace KernelPanic.UI
         {
             packageRows.Clear();
             loadoutRows.Clear();
+            selectedRunLanguages.Clear();
             cardLoadout.ClearAll();
             runSetupList?.Clear();
             runSetupDetail?.Clear();
@@ -634,6 +670,8 @@ namespace KernelPanic.UI
 
             selectedPackageIndex = (index + packageRows.Count) % packageRows.Count;
             cardLoadout.ClearLoadout(playerCollection.OwnedUnits[selectedPackageIndex]);
+            selectedRunLanguages.Clear();
+            runSetupPackageScroll = null;
             runSetupNotice = null;
             RefreshPackageSelection();
         }
@@ -650,6 +688,7 @@ namespace KernelPanic.UI
 
         private void RenderSelectedPackageDetail()
         {
+            Vector2 previousScrollOffset = runSetupPackageScroll == null ? Vector2.zero : runSetupPackageScroll.scrollOffset;
             runSetupDetail?.Clear();
             loadoutRows.Clear();
             if (runSetupDetail == null || selectedPackageIndex < 0 || selectedPackageIndex >= playerCollection.OwnedUnits.Count)
@@ -704,9 +743,31 @@ namespace KernelPanic.UI
                 packageList.ElementAt(packageList.childCount - 1).AddToClassList("package-empty");
             }
 
+            if (equippedCardIds.Count >= CardLoadout.MaxEquippedCards)
+            {
+                AddRunLanguageSelection(packageList);
+            }
+            else
+            {
+                selectedRunLanguages.Clear();
+            }
+
             packageScroll.Add(packageList);
             runSetupDetail.Add(packageScroll);
-            runSetupDetail.Add(BuildBootRow(unit, equippedCardIds.Count > 0));
+            runSetupDetail.Add(BuildBootRow(unit, CanBootRun(equippedCardIds)));
+            runSetupPackageScroll = packageScroll;
+            RestoreRunSetupPackageScroll(previousScrollOffset);
+        }
+
+        private void RestoreRunSetupPackageScroll(Vector2 offset)
+        {
+            if (runSetupPackageScroll == null)
+            {
+                return;
+            }
+
+            runSetupPackageScroll.scrollOffset = offset;
+            runSetupPackageScroll.schedule.Execute(() => runSetupPackageScroll.scrollOffset = offset).StartingIn(0);
         }
 
         private VisualElement BuildRunSetupReadout(DistroDefinition unit)
@@ -815,6 +876,80 @@ namespace KernelPanic.UI
             return row;
         }
 
+        private void AddRunLanguageSelection(VisualElement packageList)
+        {
+            IReadOnlyList<LanguageCatalogEntry> availableLanguages = GetAvailableRunLanguages();
+            packageList.Add(new Label("programming languages") { name = "RunSetupLanguagesHeader" });
+            packageList.ElementAt(packageList.childCount - 1).AddToClassList("package-header");
+            packageList.ElementAt(packageList.childCount - 1).AddToClassList("run-language-header");
+
+            if (selectedRunLanguages.Count < 2)
+            {
+                packageList.Add(new Label($"select {2 - selectedRunLanguages.Count} more language(s) before booting") { name = "RunSetupLanguagesNotice" });
+                packageList.ElementAt(packageList.childCount - 1).AddToClassList("package-notice");
+            }
+
+            if (availableLanguages.Count == 0)
+            {
+                packageList.Add(new Label("no programming languages unlocked") { name = "RunSetupLanguagesEmpty" });
+                packageList.ElementAt(packageList.childCount - 1).AddToClassList("package-empty");
+                return;
+            }
+
+            for (int i = 0; i < availableLanguages.Count; i++)
+            {
+                LanguageCatalogEntry language = availableLanguages[i];
+                packageList.Add(BuildRunLanguageRow(language, IsRunLanguageSelected(language.Language)));
+            }
+        }
+
+        private VisualElement BuildRunLanguageRow(LanguageCatalogEntry language, bool selected)
+        {
+            VisualElement row = new();
+            row.AddToClassList("package-row");
+            row.AddToClassList("run-language-row");
+            row.EnableInClassList("equipped", selected);
+            row.RegisterCallback<ClickEvent>(_ => ToggleRunLanguage(language.Language));
+
+            VisualElement summary = new();
+            summary.AddToClassList("package-summary");
+            summary.Add(new Label(selected ? "[x]" : "[ ]") { name = "RunSetupLanguageMarker" });
+            summary.ElementAt(0).AddToClassList("package-marker");
+
+            summary.Add(new Label(language.DisplayName) { name = "RunSetupLanguageName" });
+            summary.ElementAt(1).AddToClassList("package-name");
+
+            summary.Add(new Label(language.ResolutionTrack.ToString()) { name = "RunSetupLanguageTrack" });
+            summary.ElementAt(2).AddToClassList("package-meta");
+            row.Add(summary);
+
+            row.Add(new Label(language.IdentityTag) { name = "RunSetupLanguageDescription" });
+            row.ElementAt(1).AddToClassList("package-description");
+            return row;
+        }
+
+        private void ToggleRunLanguage(Language language)
+        {
+            if (IsRunLanguageSelected(language))
+            {
+                selectedRunLanguages.Remove(language);
+                runSetupNotice = null;
+                RenderSelectedPackageDetail();
+                return;
+            }
+
+            if (selectedRunLanguages.Count >= 2)
+            {
+                runSetupNotice = "language limit reached";
+                RenderSelectedPackageDetail();
+                return;
+            }
+
+            selectedRunLanguages.Add(language);
+            runSetupNotice = null;
+            RenderSelectedPackageDetail();
+        }
+
         private void ToggleCardInSelectedLoadout(DistroDefinition unit, CardDefinition card)
         {
             runSetupNotice = TryToggleLoadoutCard(unit, card);
@@ -851,6 +986,39 @@ namespace KernelPanic.UI
             return false;
         }
 
+        private IReadOnlyList<LanguageCatalogEntry> GetAvailableRunLanguages()
+        {
+            List<LanguageCatalogEntry> available = new();
+            IReadOnlyList<LanguageCatalogEntry> languages = LanguageCatalog.All;
+            for (int i = 0; i < languages.Count; i++)
+            {
+                if (LanguageUnlock.IsUnlocked(languages[i].Language, playerCollection))
+                {
+                    available.Add(languages[i]);
+                }
+            }
+
+            return available;
+        }
+
+        private bool IsRunLanguageSelected(Language language)
+        {
+            for (int i = 0; i < selectedRunLanguages.Count; i++)
+            {
+                if (selectedRunLanguages[i] == language)
+                {
+                    return true;
+                }
+            }
+
+            return false;
+        }
+
+        private bool CanBootRun(IReadOnlyList<string> equippedCardIds)
+        {
+            return equippedCardIds.Count >= CardLoadout.MaxEquippedCards && selectedRunLanguages.Count == 2;
+        }
+
         private static string FormatLoadoutFailure(CardLoadoutFailureReason reason)
         {
             return reason switch
@@ -890,9 +1058,18 @@ namespace KernelPanic.UI
 
             DistroDefinition unit = playerCollection.OwnedUnits[selectedPackageIndex];
             IReadOnlyList<string> equippedCardIds = cardLoadout.GetEquippedCardIds(unit.Id);
-            if (equippedCardIds.Count < 1)
+            if (equippedCardIds.Count < CardLoadout.MaxEquippedCards)
             {
-                runSetupNotice = "boot: no packages staged";
+                runSetupNotice = equippedCardIds.Count == 0
+                    ? "boot: no packages staged"
+                    : $"boot: stage {CardLoadout.MaxEquippedCards} packages";
+                RenderSelectedPackageDetail();
+                return;
+            }
+
+            if (selectedRunLanguages.Count < 2)
+            {
+                runSetupNotice = "boot: select 2 programming languages";
                 RenderSelectedPackageDetail();
                 return;
             }
@@ -950,6 +1127,7 @@ namespace KernelPanic.UI
         private void ShowMainMenu()
         {
             cardLoadout.ClearAll();
+            selectedRunLanguages.Clear();
             runSetupNotice = null;
             ShowPanel(mainMenuPanel);
             root.Focus();
@@ -961,35 +1139,50 @@ namespace KernelPanic.UI
             ShowPanel(collectionPanel);
         }
 
-        private void ShowCollectionUnits()
+        private void HandleCollectionBack()
         {
-            collectionShowingCards = false;
+            if (collectionScreen.BackFromSubview())
-            collectionUnitsButton.EnableInClassList(SelectedClassName, true);
+            {
-            collectionCardsButton.EnableInClassList(SelectedClassName, false);
+                SyncCollectionFrame();
-            collectionFrame.SetTitle("$ ls ~/collection");
+                return;
-            collectionScreen.RefreshUnits(playerCollection.OwnedUnits);
+            }
+
+            ShowMainMenu();
         }
 
-        private void ShowCollectionCards()
+        private void ShowCollectionUnits()
         {
-            collectionShowingCards = true;
+            collectionShowingLanguages = false;
+            collectionUnitsButton.EnableInClassList(SelectedClassName, true);
+            collectionLanguagesButton.EnableInClassList(SelectedClassName, false);
+            collectionScreen.RefreshUnits(playerCollection.OwnedUnits);
+            SyncCollectionFrame();
+        }
+
+        private void ShowCollectionLanguages()
+        {
+            collectionShowingLanguages = true;
             collectionUnitsButton.EnableInClassList(SelectedClassName, false);
-            collectionCardsButton.EnableInClassList(SelectedClassName, true);
+            collectionLanguagesButton.EnableInClassList(SelectedClassName, true);
-            DistroDefinition featuredUnit = playerCollection.FeaturedUnit;
+            collectionScreen.ShowLanguages();
-            string distroId = featuredUnit == null ? "--" : featuredUnit.Id;
+            SyncCollectionFrame();
-            collectionFrame.SetTitle($"$ dpkg -l --distro={distroId}");
-            collectionScreen.RefreshCards(playerCollection.FeaturedUnit);
         }
 
         private void ToggleCollectionTab()
         {
-            if (collectionShowingCards)
+            if (collectionShowingLanguages)
             {
                 ShowCollectionUnits();
                 return;
             }
 
-            ShowCollectionCards();
+            ShowCollectionLanguages();
+        }
+
+        private void SyncCollectionFrame()
+        {
+            collectionFrame.SetTitle(collectionScreen.CurrentTitle);
+            collectionFrame.SetHint(collectionScreen.CurrentHint);
         }
 
         private void ShowGacha()

Assets/UI/CollectionScreen.uxml

@@ -7,7 +7,7 @@
             <ui:VisualElement class="screen-frame-content">
                 <ui:VisualElement class="collection-actions">
                     <ui:Button name="CollectionUnitsButton" text="units" focusable="false" class="collection-tab" />
-                    <ui:Button name="CollectionCardsButton" text="cards" focusable="false" class="collection-tab" />
+                    <ui:Button name="CollectionLanguagesButton" text="languages" focusable="false" class="collection-tab" />
                 </ui:VisualElement>
                 <ui:VisualElement name="CollectionContent" class="collection-shell">
                     <ui:ScrollView name="CollectionList" class="collection-list" />

Assets/UI/MainMenu.uss

@@ -528,9 +528,11 @@ Button {
 }
 
 .collection-tab {
-    width: 92px;
+    min-width: 92px;
     height: 30px;
     margin-right: 10px;
+    padding-left: 10px;
+    padding-right: 10px;
     border-bottom-width: 2px;
     border-bottom-color: transparent;
     background-color: transparent;
@@ -612,6 +614,10 @@ Button {
     border-left-color: var(--kp-primary);
 }
 
+.collection-row.locked {
+    opacity: 0.55;
+}
+
 .collection-row-name {
     font-size: 16px;
     -unity-font-style: bold;
@@ -635,6 +641,18 @@ Button {
     margin-bottom: 12px;
 }
 
+.collection-command-row {
+    margin-top: 18px;
+}
+
+.collection-command-row .command-description {
+    width: 190px;
+}
+
+.collection-card-row {
+    margin-top: 6px;
+}
+
 .detail-section-title {
     color: var(--kp-primary);
     -unity-font-style: bold;
@@ -667,6 +685,10 @@ Button {
     margin-bottom: 6px;
 }
 
+.run-language-header {
+    margin-top: 14px;
+}
+
 .package-notice {
     color: var(--kp-amber);
     margin-bottom: 8px;