chore(ui): upgrade frontend dependencies

Upgrade all UI dependencies to latest compatible versions:

Dependencies:
- next: 16.1.4 → 16.1.6
- react: 19.2.3 → 19.2.4
- react-dom: 19.2.3 → 19.2.4
- react-hook-form: 7.71.1 → 7.71.2
- lucide-react: 0.562.0 → 0.577.0
- tailwind-merge: 3.4.0 → 3.5.0
- zod: 4.3.5 → 4.3.6
- zustand: 5.0.10 → 5.0.11
- @a2a-js/sdk: 0.3.8 → 0.3.10
- sonner: 2.0.7 → 2.0.9

Dev dependencies:
- @types/node: 25.0.9 → 25.4.0
- @types/react: 19.2.9 → 19.2.14
- eslint-config-next: 16.1.4 → 16.1.6
- @eslint/eslintrc: 3.3.3 → 3.3.5
- @jest/globals: 30.2.0 → 30.3.0
- jest: 30.2.0 → 30.3.0
- jest-environment-jsdom: 30.2.0 → 30.3.0
- cypress: 15.9.0 → 15.11.0
- msw: 2.12.7 → 2.12.10
- postcss: 8.5.6 → 8.5.8
- autoprefixer: 10.4.23 → 10.4.27
- start-server-and-test: 2.1.3 → 2.1.5

Skipped major upgrades (require migration):
- eslint 9.x → 10.x
- tailwindcss 3.x → 4.x

Verified: lint passes, build succeeds, all 107 tests pass.

Signed-off-by: Jaison Paul <paul.jaison@gmail.com>

Author: jsonmp-k8