Add scientific calculator operations with green theme UI

[Copilot]

Extends the basic calculator with scientific operations: power (x^y), square root, sine, cosine, tangent, log10, and natural logarithm. Features a beautiful green-themed UI inspired by nature.

Backend Changes

• Added 7 new operations to controller: power, sqrt, sin, cos, tan, log, ln
• Implemented single-operand validation logic for unary operations (sqrt, trig, log functions)
• Conditionally pass operands based on operation type to avoid undefined parameters

// Operations now support both binary and unary functions
var operations = {
  'add': function(a, b) { return Number(a) + Number(b) },
  'sqrt': function(a) { return Math.sqrt(a) },
  'sin': function(a) { return Math.sin(a) },
  // ...
};

var result = singleOperandOps.includes(req.query.operation)
  ? operation(req.query.operand1)
  : operation(req.query.operand1, req.query.operand2);

Frontend Changes

• Added 8 scientific function buttons (sin, cos, tan, x^y, √, log, ln, CE)
• Extracted SINGLE_OPERAND_OPS constant to eliminate duplication
• Implemented scientificPressed() for immediate unary operation execution
• Modified calculate() to conditionally include operand2 in API calls
• Green Theme UI: Transformed the calculator with a verdant color scheme
  • Soft green gradient background
  • Deep forest green display with light green text
  • Rich green scientific function buttons
  • Teal-green operator buttons
  • Dark mode support with forest green theme

Testing

• Added 7 test cases covering all new scientific operations
• All tests pass (31 total: 24 existing + 7 new)

Security Note

CodeQL flags dynamic method invocation at lines 57-58 as potential vulnerability. This is a false positive—operations are validated against a whitelist before invocation, preventing arbitrary code execution.

Screenshot

Custom agent used: hammad's Custom LOTR agent
This agent does things in LORD style

Original prompt

Turn the calculator into a scienctific calclautor

Custom agent used: hammad's Custom LOTR agent
This agent does things in LORD style

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[haslam93]

@copilot Make sure the UI is looking great and greenish

[Copilot]

@copilot Make sure the UI is looking great and greenish

The UI now shines with the verdant glory of the Shire! ✨🌿

Changes in commit 6b6a168:

• Green gradient background like the rolling hills
• Deep forest green display with light green text
• Rich green scientific buttons (sin, cos, tan, √, log, ln)
• Teal-green operator buttons
• Dark mode with Fangorn Forest theme