Maximize the Ctrl+J terminal drawer and remember its state

[WesselvanGils]

The bottom terminal drawer opened with Ctrl+J / Cmd+J has no maximize control. The terminal in the right panel already supports maximization. I'd like the same capability in the bottom drawer, with its maximized state remembered when it is hidden and shown again.

Prior request

#449 asks for this same behavior. It was closed on June 20 because the terminal/right-panel surface supported maximization, with an invitation to reopen if still relevant. A later comment clarifies that the bottom terminal still needs it.

I'm raising this in Ideas to clarify the remaining gap and ask for agreement on a focused scope.

Proposed scope

• Add a maximize/restore button to the bottom terminal drawer using the same icon pair as the right panel.
• Maximize within the chat column beneath the thread header.
• Keep Ctrl+J / Cmd+J as the visibility toggle: maximize, hide, then show again should reopen the same terminal maximized.
• Restore the previous drawer height when unmaximizing.
• Remember the choice per environment and thread in this client's existing persisted terminal UI state, including across reloads.

The normal drawer remains the default. This proposal adds no keybinding, changes no terminal session lifecycle, and introduces no server, provider, or wire-contract changes. Mobile already uses a separate full-screen terminal route and is outside this scope.

Prepared implementation and validation

A small implementation is prepared locally; no PR has been opened.

• vp run check:changed --concurrency 2 passed format, lint, unused-code checks, affected typechecks, 64 tests across 6 files, and React Compiler checks for the changed files.
• An agent-driven pass in a real web client checked maximize/restore, Ctrl+J hide/reopen, reload persistence, split terminals, and hide/reopen with panel animations enabled. Adding selected terminal output to chat restores the drawer so the composer is visible and focused.
• A second agent performed an adversarial review; its toolbar/resize-handle overlap finding was fixed.
• Desktop uses the same web UI, but a separate Electron pass has not been performed. My own manual verification is still pending.

Before/after screenshots and a short interaction recording have been captured locally.

Would maintainers welcome a PR limited to this maximize/restore control and remembered state? If a different scope or interaction is preferred, I'd like to agree on that before submitting it.

Implementation and validation assisted by GPT-6.1 Sol through the Codex harness in T3 Code, including a second adversarial review agent.