[Repo Assist] Fix record copy expression indentation when nested in parentheses

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Closes #2529

Root Cause

When a record copy expression (e.g. { r with Z = 1 }) was nested inside parentheses like:

let b =
    (({ r with
            Z = 1
            X = "value" }))
```

the formatter produced fields indented at the same column as `r`, violating F#'s offside rule:

```
error FS0010: Unexpected keyword 'with' or incomplete expression
```

In `genMultilineRecordCopyExpr`, `atCurrentColumnIndent` temporarily uses the copy expression's column (e.g. 8) as a "current column" anchor, then restores the outer indent (4) after writing the expression. When `indent` then runs, it adds `IndentSize` (4) to that restored outer indent → 8, which is the **same column** as `r`. The F# offside rule requires fields to be **strictly** to the right, so the formatted output would not compile.

## Fix

Before calling `atCurrentColumnIndent`, capture both `ctx.Column` (the copy expression start column) and `ctx.WriterModel.Indent` (the previous indent level). After `indent` runs, if the resulting indent level is at or below the copy expression column, bump it to `copyExprStartColumn + IndentSize`. At the end, use `RestoreIndent oldIndent` to correctly restore the saved level regardless of the bump.

## Trade-offs

- The fix is surgical — only `genMultilineRecordCopyExpr` is changed, and only when the nested-paren pathological case is detected (`Indent <= copyExprStartColumn`).
- In normal non-nested cases the condition is false and no bump occurs, so there is no change in existing formatting behaviour.
- Full test suite (2770 tests) passes.

## Test Status

```
Passed!  - Failed: 0, Passed: 2770, Skipped: 7, Total: 2777

A regression test was added to AlignedMultilineBracketStyleTests.fs covering the exact scenario from issue #2529.

Note: this supersedes the earlier draft PR #3297 which targeted an older base and is now 31 commits behind main.

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