chore(release): bump version to v1.2.7

[vitormattos]

Release 1.2.7

This is a patch release from v1.2.6.

Changes since v1.2.6

• harden PDF.js for strict CSP environments by disabling eval-based execution and embedded PDF scripting (fix: harden PDF.js for strict CSP #115)
• add CSP regression coverage for PDF rendering
• improve accessibility checks and resize handle labeling
• add Playwright end-to-end coverage for loading PDFs and editor interactions
• add package quality gates and package smoke tests
• update PDF.js and development/tooling dependencies
• update GitHub Actions dependencies and CI maintenance

Version bump

• package.json: 1.2.6 -> 1.2.7
• package-lock.json: 1.2.6 -> 1.2.7

After this PR is merged, the normal release process can create/publish v1.2.7 and trigger the npm publication workflow.