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)

tests/test_utils.gd

@@ -0,0 +1,74 @@
+class_name TestUtils
+extends RefCounted
+
+static var _test_name: String = ""
+static var _passed: int = 0
+static var _failed: int = 0
+
+static func set_test_name(name: String) -> void:
+    _test_name = name
+    _passed = 0
+    _failed = 0
+
+static func assert_equals(expected: Variant, actual: Variant, message: String) -> void:
+    if expected == actual:
+        print("[PASS] %s: %s" % [_test_name, message])
+        _passed += 1
+    else:
+        print("[FAIL] %s: %s (expected %s, got %s)" % [
+            _test_name, message, str(expected), str(actual)
+        ])
+        _failed += 1
+
+static func assert_true(condition: bool, message: String) -> void:
+    if condition:
+        print("[PASS] %s: %s" % [_test_name, message])
+        _passed += 1
+    else:
+        print("[FAIL] %s: %s" % [_test_name, message])
+        _failed += 1
+
+static func assert_false(condition: bool, message: String) -> void:
+    if not condition:
+        print("[PASS] %s: %s" % [_test_name, message])
+        _passed += 1
+    else:
+        print("[FAIL] %s: %s (expected false, got true)" % [_test_name, message])
+        _failed += 1
+
+static func assert_greater_than(a: float, b: float, message: String) -> void:
+    if a > b:
+        print("[PASS] %s: %s" % [_test_name, message])
+        _passed += 1
+    else:
+        print("[FAIL] %s: %s (expected %s > %s)" % [_test_name, message, str(a), str(b)])
+        _failed += 1
+
+static func assert_greater_or_equal(a: float, b: float, message: String) -> void:
+    if a >= b:
+        print("[PASS] %s: %s" % [_test_name, message])
+        _passed += 1
+    else:
+        print("[FAIL] %s: %s (expected %s >= %s)" % [_test_name, message, str(a), str(b)])
+        _failed += 1
+
+static func assert_not_null(value: Variant, message: String) -> void:
+    if value != null:
+        print("[PASS] %s: %s" % [_test_name, message])
+        _passed += 1
+    else:
+        print("[FAIL] %s: %s" % [_test_name, message])
+        _failed += 1
+
+static func get_passed() -> int:
+    return _passed
+
+static func get_failed() -> int:
+    return _failed
+
+static func print_result() -> void:
+    print("[SUMMARY] %s: %d passed, %d failed" % [_test_name, _passed, _failed])
+    if _failed == 0:
+        print("[RESULT] PASS")
+    else:
+        print("[RESULT] FAIL")