fix(PlaygroundLogger): use String(describing:) for CustomStringConvertible in generateSummary to remove extra debug quotes

[AkshatRaj00]

Summary

This PR fixes a display bug in PlaygroundLogger where the Playground sidebar shows unwanted surrounding quotes for user-defined CustomStringConvertible types.

File: PlaygroundLogger/PlaygroundLogger/LogEntry+Reflection.swift
Related Issue: #81

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The Bug

generateSummary() used String(reflecting:) for both CustomStringConvertible and CustomDebugStringConvertible:

// BEFORE (buggy)
if instance is CustomStringConvertible || instance is CustomDebugStringConvertible {
    return String(reflecting: instance)
}

String(reflecting:) is designed for debug output — it calls debugDescription or CustomReflectable, and adds surrounding quotes for String values and similar types. When a user implements CustomStringConvertible expecting their .description to appear in the sidebar, they instead see their output wrapped in extra quotes:

struct Greeting: CustomStringConvertible {
    var description: String { return "Hello, Playground!" }
}
let g = Greeting()
// Sidebar shows: "Hello, Playground!"  ← extra quotes from String(reflecting:)
// Expected:      Hello, Playground!

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The Fix

Split the check into two separate branches:

// AFTER (fixed)
// Use String(describing:) for CustomStringConvertible — calls .description directly,
// no debug decoration added.
if instance is CustomStringConvertible {
    return String(describing: instance)
}

// Only use String(reflecting:) for types that are *solely* CustomDebugStringConvertible.
if instance is CustomDebugStringConvertible {
    return String(reflecting: instance)
}

String(describing:) calls .description directly without any wrapping — exactly what the Playground sidebar should show for user-defined types.

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Before / After

Type	Before	After
struct implementing CustomStringConvertible	"Hello, Playground!" (extra quotes)	Hello, Playground! ✅
class implementing CustomStringConvertible	"MyClass description" (extra quotes)	MyClass description ✅
Type implementing only CustomDebugStringConvertible	Same behavior	Same behavior ✅
Plain String (handled by the earlier as? String branch)	Unchanged	Unchanged ✅

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Scope of Change

• 1 file changed: PlaygroundLogger/PlaygroundLogger/LogEntry+Reflection.swift
• 2 lines changed in generateSummary() — one || condition split into two separate if blocks
• No API changes, no behaviour changes for types not conforming to either protocol

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Reported and fixed as part of open-source contribution.