Codev client on the t3code server: workspace/architect/builder tree, tiled builder panes, mobile and remote

[pseudoseed]

Goal

Replace Tower's PTY/terminal layer and the v2 client with a Codev client written against a self-hosted t3code server.

Codev keeps porch, protocols, gates, specs/plans/reviews, CMAP, and the architect/builder model. t3code provides process control, worktrees, interrupts, remote access, mobile, and multi-machine.

Wanted UI

• Left sidebar tree: workspace → architects → that architect's builders, with live status on every row (working / turning / gated).
• Tiled builder panes inside a workspace so 4-6 builders are visible at once, plus a pane for the architect.
• Mobile pages through the same content rather than tiling.
• Reachable from an iPad over the tailnet, served from a Mac or Mac Studio.
• One client connected to more than one machine's server at once.

Verified before filing

• Headless drive of a t3code session works: a 262-line Node client authenticated via OAuth token exchange, created a worktree-backed thread, started a turn, streamed typed events, and interrupted a running turn. SHOULD_NOT_FINISH never printed — a real process kill, not a simulated keystroke. Script and log at /Users/chris/dev/t3code-spike/.
• Fully self-hosted. docs/internals/t3-connect.md: "T3 Connect is disabled in a fresh clone." Their Clerk relay is opt-in.
• Remote access over a tailnet without cloud: npx t3 pair --tailscale.
• Multi-environment connection from one client is documented.
• MIT licensed.
• Interrupted turns report session status ready, not interrupted. activeTurnId: null is the settled signal.

Not yet verified — gating this issue

1. A thread surviving a long multi-turn protocol run with shell commands executed externally between turns.
2. A porch gate: pausing a thread indefinitely, approving out of band, and resuming the same thread.
3. Stability of the t3code RPC contract over time.

Known gaps t3code does not cover

• No workspace/architect/builder tree. Its sidebar is a flat pinned thread list.
• No tiling of multiple threads. Split view exists only for terminals within one thread.
• No gate concept. Session status is starting/running/ready/settled; a builder blocked on plan-approval looks identical to one that finished. Porch would encode gate state via thread.meta.update title, thread.pin, and thread.activity.append.