fix(tui): refine action span priority and in-place line alignment

[HarshK97]

Problem

1. When a variable declaration like var fc = func(...) got refactored to fc := func(...), the inner func_literal was parsed as a Move action because its parent changed from var_spec to short_var_declaration. AlignLines flagged the whole block as an unalignable move, creating diagonal filler lines (///) on both sides and splitting the function body into two separated blocks instead of rendering line 850 side-by-side.
2. In the TUI renderer, outer container highlights (like a wide 138-byte delete of var_declaration) were taking visual priority over inner child highlights (like a 129-byte move of func_literal). mergeAllSpans was also dropping the underlying AST byte span when merging adjacent line highlights, creating fake single-line lengths that swallowed inner action highlights.

What Changed

• Relative Container Position Alignment: Updated isDisplacedMove in internal/serialize/align.go to calculate line offsets relative to the nearest mapped enclosing container. If a node stays inside the same mapped function or block at the same relative line offset, it is recognized as an in-place structural shift rather than a relocated move, so AlignLines pairs lines side-by-side with zero diagonal filler lines inside the function.
• Span Priority by Total AST Byte Length: Added totalLen to span in internal/tui/highlight.go, propagating max(curr.totalLen, next.totalLen) when merging adjacent line highlights so wider container spans don't drop their true total length.
• TUI Action Priority Tie-Breaking: Updated renderStyledLine in internal/tui/view.go to select highlights based on totalLen so narrower inner AST actions override wider outer container spans, with action kind tie-breaking preferring specific move and update actions over container insert and delete.
• Test Baseline Expectations: Updated golden expected.json files across integration test fixtures to match the improved side-by-side line alignment.

Visual Comparison:

Example :- tests/testdata/go_gin_fix_lint

Before

After