refactor: migrate jumpToState to Astro.licals to prevent build-time state leakage

[riya-saharan]

This PR addresses the issue of state leakage across different locales during parallel static builds.

The Problem:
Previously, the jumpToState (used for the "Jump To" sidebar) was managed via a global singleton in src/globals/state.ts. During high-concurrency builds, pages from different locales (e.g., Korean and Chinese) would overwrite this global variable, leading to incorrect translations appearing on the wrong pages.

The Solution:
I have migrated the state management to Astro.locals, which provides an isolated data store for every unique request/page build.

Key Changes:

State Isolation: Moved jumpToState into App.Locals via env.d.ts.

Component Updates: Refactored Nav.astro, NavPanels.tsx, and Settings.tsx to consume state from the request context.

Thread-Safety: Removed the global variable and setter from state.ts.

Lifecycle Management: Updated all layouts and localized page entry points to explicitly set or reset their own jumpToState within the Astro.locals scope.

Verification:
Successfully passed npm run build with 0 errors. Verified language isolation in a local preview environment across multiple localized routes.