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)

core/prestige/prestige_progress_bar.tscn

@@ -0,0 +1,22 @@
+[gd_scene format=3]
+
+[ext_resource type="Script" path="res://core/prestige/prestige_progress_bar.gd" id="1_pbg"]
+
+[node name="PrestigeProgressBar" type="HBoxContainer"]
+offset_right = 298.0
+offset_bottom = 49.0
+alignment = 1
+script = ExtResource("1_pbg")
+
+[node name="LabelStart" type="Label" parent="."]
+layout_mode = 2
+text = "0"
+
+[node name="ProgressBar" type="ProgressBar" parent="."]
+custom_minimum_size = Vector2(200, 0)
+layout_mode = 2
+show_percentage = true
+
+[node name="LabelEnd" type="Label" parent="."]
+layout_mode = 2
+text = "0"