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).

docs/API.md

@@ -1767,7 +1767,7 @@ DELETE /api/run/:id                   Kill (SIGTERM → SIGKILL after 5 s)
 
 **`POST /api/run` (start/attach):** Requires `laneId` (the lane this run belongs to). Creates or attaches an existing tmux session named `agenthub-lane-<id>` in the lane's working directory. If that session already exists and its pane is idling at a shell prompt, the appropriate command line (including `--resume` and any initial prompt) is typed into that pane instead of being dropped; if the pane is running a program, the request adopts the session unchanged. Optionally accepts `initialPrompt` to immediately type/send into the session (if empty or omitted, the session is created/attached with no initial input). Returns `{ id, laneId, status, cwd, model, permissionMode, effort, resumeSessionId, sessionId, startedAt, promptPreview }` where `id` is the tmux session name. The dashboard self-heals a lane's `run_id`/`status` on every read if the tmux session has been killed externally.
 
-`permissionMode` (`acceptEdits` default, or `default` / `plan` / `bypassPermissions`) is the mode the pane starts in. The pane's argv also carries `--allow-dangerously-skip-permissions`, which only makes **bypass permissions** selectable in the pane's `shift+tab` cycle — it does not enable it.
+`permissionMode` (`auto` default, or `acceptEdits` / `default` / `plan` / `bypassPermissions`) is the mode the pane starts in — `auto` is the CLI's own classifier mode: it asks only for what it reads as risky. The pane's argv also carries `--allow-dangerously-skip-permissions`, which only makes **bypass permissions** selectable in the pane's `shift+tab` cycle — it does not enable it.
 
 **PTY streaming:** Frames from the tmux pane are streamed to the client over `/ws-pty/:runId` as binary WebSocket frames (not JSON). The Workspace page's TerminalView component feeds these frames to xterm.js for live rendering. Simultaneously, `agenthub lanes shell` can attach the same session via a real local terminal, staying in sync with the browser view.
 
@@ -1990,7 +1990,7 @@ Sent when a notification is created.
 
 #### /ws-pty/:runId — PTY frames
 
-A dedicated binary WebSocket stream (not JSON-framed) for tmux-backed PTY transport. Established by the Workspace TerminalView component on lane load; endpoint is `/ws-pty/:runId` where `runId` comes from `POST /api/run`. Frames are raw PTY output (stdin echoes, command output, prompt updates, terminal control sequences) as binary blobs; the client feeds each frame to xterm.js for live rendering. The same tmux session can have multiple simultaneous clients (browser Workspace, `agenthub lanes shell`, other tools), all receiving the same frames live-synced. Resize events: the client sends a `{"type":"resize","cols","rows"}` text frame and the server applies it as a `TIOCSWINSZ` ioctl down the pane's pty, so window-sensitive commands (e.g. pagers, text editors) adapt to the viewport size. The client reports its size from **xterm's own `onResize`**, not from the container's `ResizeObserver` — cols also move when the webfont finishes loading or the page zooms, neither of which resizes the observed element — and re-asserts it whenever the terminal regains focus, because `window-size latest` lets a second attach client (another tab, `agenthub lanes shell`) resize the tmux window out from under this one. Keeping the two widths equal is not cosmetic: a tmux pane **wider** than xterm makes every over-long row autowrap its tail onto the next row's left margin, and tmux never repaints a row it believes unchanged — so stray characters stay glued to the left edge of blank lines, visible as soon as a scroll repaints history. A zero size (the console collapses with CSS, leaving the container 0×0) is never reported. The WebSocket connection inherits the same loopback same-origin guard and optional token auth as other `/api/*` routes. The client re-attaches automatically 1.5 s after an unexpected close (server restart, network blip) — tmux keeps the session alive, so the re-attach repaints the pane in full. It stops retrying only after the server's one-shot `{"type":"exit"}` frame, which means the pane process itself ended. Without that retry a dropped socket left the pane frozen on its last painted frame: it still looked live, but no keystroke and no mouse report (wheel scroll included) reached tmux again.
+A dedicated binary WebSocket stream (not JSON-framed) for tmux-backed PTY transport. Established by the Workspace TerminalView component on lane load; endpoint is `/ws-pty/:runId` where `runId` comes from `POST /api/run`. Frames are raw PTY output (stdin echoes, command output, prompt updates, terminal control sequences) as binary blobs; the client feeds each frame to xterm.js for live rendering. The same tmux session can have multiple simultaneous clients (browser Workspace, `agenthub lanes shell`, other tools), all receiving the same frames live-synced. **The attach URL carries the client's size** (`/ws-pty/:runId?cols=<n>&rows=<n>`, integers in `[2, 1000]`, else 80×24): tmux resizes the window to whichever client attached most recently, so spawning the attach at a default size and correcting it from the first `resize` message a beat later made the pane's program redraw its whole UI at 80 columns — and everything painted at that width stayed in the scrollback, surfacing as torn left-margin fragments the moment the user scrolled back (issue #33). Resize events after that: the client sends a `{"type":"resize","cols","rows"}` text frame and the server applies it as a `TIOCSWINSZ` ioctl down the pane's pty, so window-sensitive commands (e.g. pagers, text editors) adapt to the viewport size. The client reports its size from **xterm's own `onResize`**, not from the container's `ResizeObserver` — cols also move when the webfont finishes loading or the page zooms, neither of which resizes the observed element — and re-asserts it whenever the terminal regains focus, because `window-size latest` lets a second attach client (another tab, `agenthub lanes shell`) resize the tmux window out from under this one. Keeping the two widths equal is not cosmetic: a tmux pane **wider** than xterm makes every over-long row autowrap its tail onto the next row's left margin, and tmux never repaints a row it believes unchanged — so stray characters stay glued to the left edge of blank lines, visible as soon as a scroll repaints history. A zero size (the console collapses with CSS, leaving the container 0×0) is never reported. The WebSocket connection inherits the same loopback same-origin guard and optional token auth as other `/api/*` routes. The client re-attaches automatically 1.5 s after an unexpected close (server restart, network blip) — tmux keeps the session alive, so the re-attach repaints the pane in full. It stops retrying only after the server's one-shot `{"type":"exit"}` frame, which means the pane process itself ended — the Workspace takes that frame as the signal to restore the run setup form, since there is nothing left to attach to. Without that retry a dropped socket left the pane frozen on its last painted frame: it still looked live, but no keystroke and no mouse report (wheel scroll included) reached tmux again.
 
 #### cc_config_changed