Fix multiline ternary expression formatting with tabs

[Copilot]

• [x] Understand the issue: multiline ternary expressions with tabs are being formatted with mixed tabs and spaces
• [x] Create a test to reproduce the issue
• [x] Investigate the root cause in the indentation calculation logic
• [x] Fix the indentation calculation for conditional expression branches
• [x] Verify the fix with the test
• [x] Run all format tests to ensure no regressions
• [x] Clean up accidental patch files
• [x] Run format, lint, and test commands
• [x] Move test to format_test.go and assert specific output

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Bad formatting of multiline ternary expression</issue_title> <issue_description>From https://github.com/microsoft/TypeScript/issues/14494 (original issue was actually fixed in 6, but regressed here)

Format the following code that uses tabs for indentation :

const test = (a: string) => (
	a === '1' ? (
		10
	) : (
		12
	)
)

Bug You get a mix of tabs and spaces:

const test = (a: string) => (
	a === '1' ? (
   10
	) : (
   12
	)
)
```</issue_description>

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

<comments>
</comments>

• Fixes microsoft/typescript-go#2201

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