[BUG] V1 edit.ts isDisproportionateMatch bypasses all safety checks for single-line oldString

Description

packages/opencode/src/tool/edit.ts line 742: the isDisproportionateMatch() function returns false immediately when oldString is a single line, bypassing all safety checks. This allows fuzzy replacers like LineTrimmedReplacer to match significantly larger blocks than intended.

Root Cause

function isDisproportionateMatch(search: string, oldString: string) {
  const oldLines = oldString.split("\n").length
  const searchLines = search.split("\n").length
  if (searchLines >= Math.max(oldLines + 3, oldLines * 2)) return true
  if (oldLines === 1) return false  // <-- BUG: bypasses all checks
  return search.trim().length > Math.max(oldString.trim().length + 500, oldString.trim().length * 4)
}

When oldString is a single line (e.g., "return value"), the function immediately returns false meaning "not disproportionate." A fuzzy replacer could match many lines where "return value" appears, modifying a much larger section than the user/AI intended.

Steps to reproduce

1. Try to edit a single line like "return result" in a large file
2. If the exact match fails and falls to fuzzy replacers
3. A much larger block containing "return result" could be matched and replaced

OpenCode version

1.17.3

已提交此问题的修复 PR #31896（device path validation, edit safety, Unicode NFC, glob/grep security）