systems rework: buffs, prestige graph, research, modular architecture

Decouples core systems from centralized globals in favor of catalogue-based architecture and data-driven content.

   Key changes:
   - Prestige: node-based buff tech tree, graph panel, progress bar
   - Research: multi-worker system, per-generator research, xp generation
   - Ascension: meta-currency layer via multi-currency prestige resets
   - Buffs: refactored as generator-independent via catalogues
   - UI: currency panel, edge-scrolling camera + zoom, current-goal panel
   - Alchemy Tower: crafting building with recipe/cost system
   - Testing: 7 test suites (ascension, prestige, research, goals)
   - Content: migrated from hardcoded idles/ to gym format (tiny_sword)

.opencode/plans/currency-panel.md

@@ -0,0 +1,97 @@
+# Plan: Create CurrencyPanel Widget
+
+## Goal
+Regroup the 9 individual CurrencyTile nodes in tiny_sword.tscn into a single dynamic `CurrencyPanel` widget that automatically retrieves and displays all currencies from the LevelGameState catalogue.
+
+## Changes
+
+### 1. Create `CurrencyPanel` script (`core/currency/currency_panel.gd`)
+
+**New file**: `res://core/currency/currency_panel.gd`
+
+**Class**: `class_name CurrencyPanel`, extends `PanelContainer`
+
+**Structure**:
+```gdscript
+class_name CurrencyPanel
+extends PanelContainer
+
+const CURRENCY_TILE_SCENE: PackedScene = preload("res://currency_tile.tscn")
+
+@onready var _tiles_container: VBoxContainer = $CurrencyTiles
+
+var _game_state: LevelGameState
+
+func _ready() -> void:
+    _game_state = find_parent("LevelGameState")
+    if _game_state == null:
+        push_error("CurrencyPanel: No LevelGameState found in parent hierarchy")
+        return
+    _build_currency_tiles()
+    _game_state.ready.connect(_on_game_state_ready)
+
+func _build_currency_tiles() -> void:
+    # Clear existing children
+    for child in _tiles_container.get_children():
+        child.queue_free()
+    
+    if _game_state.currency_catalogue == null:
+        return
+    
+    for currency in _game_state.currency_catalogue.currencies:
+        if currency == null:
+            continue
+        var tile: CurrencyTile = CURRENCY_TILE_SCENE.instantiate()
+        # Set exports before add_child() so they're available in _ready()
+        tile.currency = currency
+        tile.game_state = _game_state
+        _tiles_container.add_child(tile)
+
+func _on_game_state_ready() -> void:
+    pass
+```
+
+**Why this works with existing CurrencyTile**: CurrencyTile uses `@export` for `currency` and `game_state`. When `instantiate()` is called, `_ready()` is NOT invoked yet - it fires when the node is added to the scene tree. By setting properties before `add_child()`, `_ready()` sees them as non-null. The DebugIncomeButton is preserved since CurrencyTile is unchanged.
+
+### 2. Update tiny_sword.tscn scene
+
+**Replace**: 9 individual CurrencyTile nodes under `LevelGameState/UI` with a single CurrencyPanel hierarchy.
+
+**Remove from scene**:
+- All 9 individual CurrencyTile nodes: `GoldCurrencyTile`, `WorkerCurrencyTile`, `FoodCurrencyTile`, `WoodCurrencyTile`, `AscensionCurrencyTile`, `MagicGoldTile`, `ManaStoneTile`, `CogniteTile`, `PhilosoperStoneTile`
+- ExtResource `7_0cs5o` (currency_tile.tscn) - no longer referenced directly
+- All 9 individual currency resource ExtResources: `9_1363k` (gold), `10_i1cck` (worker), `11_hskcg` (food), `12_l6a68` (wood), `15_ascension`, `20_no27p` (magic_gold), `22_rbyxa` (mana_stone), `23_vrcrd` (cognite), `24_eaq6h` (philosoper_stone)
+
+**Add to scene**:
+- ExtResource `8_cpnl` → `res://core/currency/currency_panel.gd`
+- New node hierarchy:
+  ```
+  LevelGameState/UI (Control, layout_mode=3)
+    CurrencyPanel (PanelContainer, layout_mode=1, pos 5,5 size 250x340, script=8_cpnl)
+      CurrencyTiles (VBoxContainer, separation=4)   ← script-less, populated at runtime
+    GoalsDebugUI (repositioned: offset_left=265)
+  ```
+
+**Keep**: GoalsDebugUI (repositioned slightly from offset_left=1275 to offset_left=265 to account for panel width)
+
+## File Structure After Changes
+
+```
+core/
+  level_game_state.gd              # unchanged (ready is built-in)
+  currency/
+    currency_panel.gd              # NEW: dynamic panel widget
+docs/gyms/tiny_sword/
+  tiny_sword.tscn                  # 9 tiles → 1 panel hierarchy (cleaner)
+```
+
+## No Changes Needed
+- **`level_game_state.gd`**: The `ready` signal is built-in for Godot nodes - no addition needed.
+- **`currency_label.gd` (CurrencyTile)**: Unchanged - DebugIncomeButton preserved.
+
+## Testing
+- Run Godot headless to verify scene loads without errors
+- Verify all 9 currencies appear in the CurrencyPanel
+- Verify currency values update on changes (currency_changed signal)
+- Verify DebugIncomeButton works on each tile
+- Verify the panel doesn't overlap with GoalsDebugUI