Not Enough Calculator

New features:

• Added pi constant (3.14159265...) for use in any expression.
• Added e constant (Euler's number, 2.71828182...) with smart conflict resolution:
• Standalone e or e after an operator = Euler's number
• e after a number (e.g. 2e, 5e) = Skyblock enchanted unit (160), same as before

pi * 2 = 6.283...
e^2 = 7.389...
2e = 320  (still enchanted unit)
ln(e) = 1

• Added factorial ! operator (postfix):

5! = 120
10! = 3,628,800
(3+2)! = 120

• Factorial is limited to non-negative integers up to 1000.

Bug fixes & code quality:

• Fixed /calcset evaluating the expression twice (causing duplicate history entries).
• Fixed isExpressionComplete() regex only checking 5 of 12 functions (was missing log, ln, sin, cos, tan, min, max).
• Fixed Ctrl+C shortcut missing from /calchelp output.
• Removed redundant searchField2 variable in Ctrl+C handler.
• Removed dead sessionResetNotified field and methods from CalculatorManager.

Documentation:

• Updated /calchelp operators to include factorial.
• Updated /calchelp variables to show pi and e as built-in constants.
• Updated /calchelp functions to include factorial examples.
• Updated README, Modrinth, and CurseForge descriptions with new features and examples.

Tests: Added 21 new test cases for pi, e, and factorial (including edge cases). Added new CalculatorManagerTest with 30+ test cases for looksLikeCalculation() heuristic.

Full Changelog: https://github.com/Rijzzz/NotEnoughCalculator/compare/v2.1.0...v2.2.0