feat(run,ui): make the lane console usable — terminal focus, live-exit recovery, auto permission mode, model aliases

Terminal (issue #33):
- `convertEol` is gone from xterm. It rewrote every bare LF as CR+LF, so a
  tmux pane that scrolled (tmux emits a bare LF and keeps drawing at the
  column it was on) had the rest of that draw land at column 0, stamping a
  line's first characters into the left margin of the rows below — the torn
  left edge that only showed up once content scrolled.
- The attach carries the client's real size (`?cols=&rows=`, `sizeFromQuery`
  in `server/websocket.js`, bounded because it reaches a TIOCSWINSZ ioctl).
  `attach()` spawned `tmux attach-session` at a hardcoded 80x24 on every
  attach, and tmux sizes the window to the newest client, so `claude` redrew
  its whole UI at 80 columns until the first `resize` message landed.
- The terminal takes the keyboard on mount, so typing reaches tmux without
  clicking the pane first.
- A pane that ends (double Ctrl+C, `exit`, a crash) reports itself through a
  new `onExit` prop and `LaneConsolePane` runs `newRun()`, so the console
  returns to the setup form instead of leaving a dead pane behind a
  "New run" button.

Pane environment:
- `server/lib/desktop-env.js` forwards the graphical session's DISPLAY /
  WAYLAND_DISPLAY / XAUTHORITY / XDG_RUNTIME_DIR (from
  `systemctl --user show-environment`, this process's own values winning)
  into the pane. The server normally runs as a systemd user service with none
  of them, so `claude` there could not read the clipboard and answered "no
  image found in clipboard" on every image paste.

Run setup:
- `auto` is a permission mode and is now the default everywhere — allowlists,
  the `--permission-mode` fallback, the select, and the pane's initial state.
- The model picker sends the CLI's aliases (`fable`/`opus`/`sonnet`/`haiku`)
  instead of pinned ids. `claude --model` resolves an alias to the latest
  model itself, so a release like Fable 5.1 needs no edit here; pricing is
  unaffected because it keys off the resolved id the transcript reports.
- **Create/update readme file** moved from the Add-lane modal into the lane's
  Tools menu: creating a lane and writing its docs are separate decisions,
  and the second is worth re-running long after the first.
- The Workspace's no-lane state is a real banner; the lane strip (add tile
  included) renders only once a lane exists.

Refs #32, #33.

Tests: npm run test:server (1828 pass), client vitest (558 pass).

server/__tests__/websocket-pty-size.test.js

@@ -0,0 +1,31 @@
+/**
+ * @file websocket-pty-size.test.js
+ * @description Regression test for issue #33: the `/ws-pty/:runId` attach
+ * spawns `tmux attach-session` at the size the CLIENT reports in the attach
+ * URL, not a hardcoded 80×24. tmux sizes the window to the newest client, so
+ * attaching at 80 columns and fixing it from the first `resize` message made
+ * `claude` redraw its whole UI at 80 columns — wreckage that stays in the
+ * scrollback and shows up as torn left-margin fragments when scrolling back.
+ * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
+ */
+const { describe, it } = require("node:test");
+const assert = require("node:assert/strict");
+const { sizeFromQuery } = require("../websocket");
+
+const query = (search) => new URL(`http://x/ws-pty/agenthub-lane-1${search}`).searchParams;
+
+describe("sizeFromQuery — the attach carries the client's real size", () => {
+  it("reads the terminal's own cols/rows", () => {
+    assert.deepEqual(sizeFromQuery(query("?cols=226&rows=29")), { cols: 226, rows: 29 });
+  });
+
+  it("falls back to 80x24 when the client named no size", () => {
+    assert.deepEqual(sizeFromQuery(query("")), { cols: 80, rows: 24 });
+  });
+
+  it("refuses anything out of bounds — this number reaches an ioctl", () => {
+    assert.deepEqual(sizeFromQuery(query("?cols=0&rows=-5")), { cols: 80, rows: 24 });
+    assert.deepEqual(sizeFromQuery(query("?cols=99999&rows=99999")), { cols: 80, rows: 24 });
+    assert.deepEqual(sizeFromQuery(query("?cols=abc&rows=12.5")), { cols: 80, rows: 12 });
+  });
+});