#Fix Key Reveal Across Projects

When switching between projects with different vault keys, attempting to reveal or copy a key would fail because the decrypt API call was missing the project context. The server would fall back to the user's first project, fail to find the key there, and return a 404.

Additionally, the cached vault key in sessionStorage was stored under a fixed key, causing stale vault keys from one project to be incorrectly reused for another project.

Both issues are now fixed: the project ID is sent with every decrypt request, and vault key caching is scoped per project.