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).

client/src/pages/__tests__/__snapshots__/screens.snapshot.test.tsx.snap

@@ -5100,13 +5100,58 @@ exports[`screen snapshots > Run 1`] = `
       class="flex min-h-0 flex-1 flex-col gap-4"
     >
       <div
-        class="flex shrink-0 flex-row gap-2 overflow-x-auto pb-1"
-        data-testid="lane-strip"
+        class="card flex shrink-0 flex-wrap items-center gap-4 border-dashed px-5 py-4"
+        data-testid="lane-empty"
       >
+        <span
+          class="flex h-10 w-10 shrink-0 items-center justify-center rounded-xl bg-surface-4 text-fg-muted"
+        >
+          <svg
+            class="lucide lucide-layers h-5 w-5"
+            fill="none"
+            height="24"
+            stroke="currentColor"
+            stroke-linecap="round"
+            stroke-linejoin="round"
+            stroke-width="2"
+            viewBox="0 0 24 24"
+            width="24"
+            xmlns="http://www.w3.org/2000/svg"
+          >
+            <path
+              d="M12.83 2.18a2 2 0 0 0-1.66 0L2.6 6.08a1 1 0 0 0 0 1.83l8.58 3.91a2 2 0 0 0 1.66 0l8.58-3.9a1 1 0 0 0 0-1.83z"
+            />
+            <path
+              d="M2 12a1 1 0 0 0 .58.91l8.6 3.91a2 2 0 0 0 1.65 0l8.58-3.9A1 1 0 0 0 22 12"
+            />
+            <path
+              d="M2 17a1 1 0 0 0 .58.91l8.6 3.91a2 2 0 0 0 1.65 0l8.58-3.9A1 1 0 0 0 22 17"
+            />
+          </svg>
+        </span>
+        <div
+          class="min-w-0 flex-1"
+        >
+          <h2
+            class="text-sm font-medium text-fg-primary"
+          >
+            No lanes yet
+          </h2>
+          <p
+            class="mt-0.5 text-xs text-fg-muted"
+          >
+            A lane is one working directory the dashboard follows — its pipeline, sessions and terminal. Add one here, or from a terminal:
+             
+            <code
+              class="rounded bg-surface-2 px-1.5 py-0.5 text-[11px] text-fg-secondary"
+            >
+              agenthub lanes add --cwd $(pwd)
+            </code>
+          </p>
+        </div>
         <button
-          class="flex w-56 shrink-0 items-center justify-center gap-1.5 rounded-lg border border-dashed border-border-light p-3 text-[13px] font-medium text-fg-secondary transition-colors hover:border-accent hover:bg-accent/5 hover:text-fg-primary"
+          class="btn-primary shrink-0"
           data-testid="lane-tile-add"
-          title="Create a lane from a working directory"
           type="button"
         >
           <svg
@@ -5130,15 +5175,6 @@ exports[`screen snapshots > Run 1`] = `
           </svg>
           Add lane
         </button>
-        <p
-          class="text-sm text-fg-muted"
-        >
-          No lanes yet. Create one from a working directory:
-           
-          <code>
-            agenthub lanes add --cwd $(pwd)
-          </code>
-        </p>
       </div>
       <section
         class="flex min-h-0 min-w-0 flex-1 flex-col "
@@ -5444,7 +5480,7 @@ exports[`screen snapshots > Run 1`] = `
                         <span
                           class="truncate"
                         >
-                          acceptEdits (recommended)
+                          auto (recommended - asks only for risky actions)
                         </span>
                         <svg
                           class="lucide lucide-chevron-down w-3.5 h-3.5 text-fg-muted flex-shrink-0"