Tree view: use normal text color with status-colored icons and counters

[Copilot]

Tree view text was fully colored by test status, reducing readability. Changed to use normal text color for test names while keeping status indicators (icons and counters) in classic green/red.

Changes

• Added GetDisplayName() and GetDisplayCounter() to TreeViewNode for independent component styling
• Created BuildDisplayText() helper to compose name (normal) + counter (status-colored)
• Updated render logic to color only icon (●) and counter (n/m), not the full text
• Fixed truncation to preserve counter visibility when names are long

Before/After

Before:

└─ ▼ ● Asynkron.TestRunner (3/3)  ← entire line colored green
   └─ ● FailingClass (1/1)        ← entire line colored red

After:

└─ ▼ ● Asynkron.TestRunner (3/3)  ← name normal, icon+counter green
   └─ ● FailingClass (1/1)        ← name normal, icon+counter red

Original prompt

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This section details on the original issue you should resolve

<issue_title>tree styling</issue_title>
<issue_description>I want a more classic gree and red for failing vs passing tests, the treeview text. should just be normal text color, the ball/circle at the front of it should be of that red/green. and the (1/1) counter could be the same red/green.</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes tree styling #15

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