fix(server): update members page to match Figma design

Polish the Members page and add search to Invitations

What changed

Members page layout

• Added the organization name as a large page title (h1) above the “Members” heading, matching the Projects page.
• Grouped the search bar + actions row, the tabs, and the table into a single members-section container with consistent spacing-7 between them (mirroring the Projects “Recent/All” sections).

Projects page

• Changed the “Recent projects” / “All projects” section titles to regular font weight (from medium).

Search in the Invitations tab

• The search input is now shown on both the All members and Invitations tabs (previously members-only).
• On the Invitations tab it filters pending invitations by invitee email; on the Members tab it filters by email/name as before.
• The search box value is bound to state and resets when switching tabs (and after sending an invite), so each tab starts with an empty box and an unfiltered list.
• When an invitations search returns no matches, the table now shows the same “no results” empty state as the members table (user_x icon + “Try changing your search term”) instead of the onboarding “No invitations created” state, which is reserved for when there are genuinely no invitations.