fix(cli): parse strings ending in escaped backslashes

[hamedrabah]

Summary

• treat a quote as escaped only when it is preceded by an odd number of backslashes
• keep payment provider parsing intact when config strings end in a literal backslash
• add a regression test covering a Windows-style output directory

Verification

• ./node_modules/.bin/vitest run packages/cli/src/commands/config.test.ts (7 tests)
• ./node_modules/.bin/tsc -p packages/cli/tsconfig.json --noEmit
• git diff --check