Increment version to 1.4.0

[gnbm]

What was done?

• Prepare v1.4.0 to make a new release (package.json bump + npm run build, regenerating dist/, dist-archive/ and docs/assets/)
• Disable Cypress video recording (video: false) — failure screenshots already cover debugging, so encoding video for every spec run was pure overhead

Does this introduce a breaking change?

• Yes
• No

This PR itself only bumps the version, rebuilds the release artifacts, and tweaks the Cypress config. The one breaking change shipping in 1.4.0 — Up/Down in the search input now navigates the option list instead of moving the text caret — was already merged to master via #485; it's called out in the release notes.

Verifications

• npm run validate (tsc + eslint + stylelint): clean, exit 0

• npm run test (Cypress e2e): 420/420 passing, 28 specs

  ✔  All specs passed!                        03:39      420      420        -        -        -
  E2E passed in 290s (28 spec(s))
  

• npm run test:scripts: 72/72

• npm run test:build: 4/4

[github-actions]

PR Test Results — ✅ all checks passed

Check	Result	Time
Typecheck	✅	3s
ESLint	✅	2s
Stylelint	✅	1s
CI Scripts	✅	1s
Build	✅	3s
a11y-aria-label.cy.ts	✅ 10/10	6s
a11y-close-clears-highlight.cy.ts	✅ 7/7	5s
a11y-escape-close.cy.ts	✅ 6/6	2s
a11y-listbox-multiselectable.cy.ts	✅ 3/3	1s
a11y-live-region.cy.ts	✅ 18/18	6s
a11y-reduced-motion.cy.ts	✅ 3/3	1s
a11y-required-error.cy.ts	✅ 20/20	4s
a11y-search-arrow-navigation.cy.ts	✅ 13/13	8s
a11y-select-all.cy.ts	✅ 7/7	3s
a11y-server-search-announcements.cy.ts	✅ 6/6	4s
a11y-target-size.cy.ts	✅ 5/5	2s
build-stylesheet-integrity.cy.ts	✅ 4/4	5s
examples.cy.ts	✅ 219/219	1m40s
observer-listener-lifecycle.cy.ts	✅ 7/7	1s
perf-resize-throttle.cy.ts	✅ 3/3	1s
perf-scroll-aria.cy.ts	✅ 6/6	4s
secure-option-values.cy.ts	✅ 2/2	1s
secure-text-warning.cy.ts	✅ 4/4	2s
security-ampersand-storage.cy.ts	✅ 16/16	3s
security-chrome-label-props.cy.ts	✅ 10/10	1s
security-classnames-xss.cy.ts	✅ 2/2	1s
security-customdata-xss.cy.ts	✅ 2/2	1s
security-global-defaults.cy.ts	✅ 11/11	1s
security-hidden-input-name.cy.ts	✅ 7/7	1s
security-proto-value.cy.ts	✅ 9/9	2s
security-quote-escaping.cy.ts	✅ 12/12	2s
tag-tooltip-overflow.cy.ts	✅ 6/6	11s
timer-cleanup.cy.ts	✅ 2/2	1s

Tested commit: d49f1d0 · Run #22