Reorganize vault action buttons and add row batch actions

Problem/Motivation

The vault overview page (/user/{uid}/vault) renders a single generic row of action buttons at the top: Add a file, Grant access, Add trusted consumer, the per-kind record-add buttons, and Lock vault. Those actions sit far from the content they relate to, so the page reads as one button bar followed by several unrelated tables.

Proposed resolution

Move each action next to the content it creates, below that section table:

• Add a file goes under the Files section.
• The per-kind "Add [kind]" record buttons go under the Structured data section.
• Grant access goes under the Active grants section.
• Add trusted consumer goes under the Consumer access section.
• Lock vault moves into Advanced, next to Vault passphrase, since it is a passphrase control. It only shows while the vault is unlocked; when locked, the prominent Unlock prompt is the action instead.

An empty section drops its placeholder table and shows just the action button. A section with neither rows nor an action (for example Access requests or Store requests when nothing is pending) is hidden entirely.

Remaining tasks

• Review the rendering.
• Merge.