fix(code-review): use new-file line numbers when parsing changed ranges

parseChangedRanges was returning hunk.oldStart/oldLines, but the ranges
are consumed against content.split('\n') (new file) and graph nodes
parsed from the PR head — so any lines added or removed earlier in the
file shifted offsets and the formatter sliced the wrong code, feeding
garbage to the reviewer.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: malinosqui

libs/code-review/infrastructure/adapters/services/graphContentFormatter.service.ts

@@ -200,8 +200,9 @@ export class GraphContentFormatter {
 
             for (const file of parsed) {
                 for (const hunk of file.hunks) {
-                    const start = hunk.oldStart;
-                    const end = start + hunk.oldLines - 1;
+                    const start = hunk.newStart;
+                    const end =
+                        hunk.newLines > 0 ? start + hunk.newLines - 1 : start;
                     if (start > 0 && end >= start) {
                         ranges.push([start, end]);
                     }