docker: two ways to talk to the loose agent

Remote Control, so a detached run is not a one-way trip:

  ./sylph-agent remote   -> https://claude.ai/code/session_...
  ./sylph-agent attach   -> the container's own terminal

`loose` now starts Claude Code with `--remote-control <name>`, registering the
session with your account so you can chat with it from claude.ai or a phone.
The name is passed EXPLICITLY because the flag's value is optional — a bare
`--remote-control` swallows the /loop prompt that follows as the session name.
Off with SYLPH_REMOTE=0, renamed with SYLPH_REMOTE_NAME.

The pty is forced to 200x50. A detached `docker run -t` gives 80x24, and Claude
Code hard-wraps to the terminal width — which truncated the Remote Control URL
to ".../session_01..." in the one place you actually need to read it, and made
`docker logs` nearly unusable besides.

`remote` waits up to six minutes and reports progress: registration lands a
minute or two after launch, so answering "not found" immediately would be
answering a different question than the one being asked.

Verified: a loose run registers and `./sylph-agent remote` prints the full URL.
`attach` is NOT verified end to end from here — `docker attach` refuses a piped
stdin ("cannot attach stdin to a TTY-enabled container"), which is a property of
this harness rather than of the container, so it needs a real terminal to try.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

docker/agent/README.md

@@ -11,6 +11,8 @@ the emulator, reads its guest memory and photographs its screen.
 ./sylph-agent shell            # poke around
 ./sylph-agent agent            # Claude Code, --dangerously-skip-permissions
 ./sylph-agent loose            # turn it loose: detached, /loop, self-paced
+./sylph-agent remote           # link to chat with it from anywhere
+./sylph-agent attach           # chat with it locally
 ./sylph-agent logs -f          # watch it
 ./sylph-agent stop             # stop it
 ```
@@ -26,8 +28,28 @@ fixed cadence instead of letting it self-pace.
 
 It runs `-d` **without** `--rm`, so the transcript survives the container
 exiting — for an unattended run that is the only record of what happened.
-`./sylph-agent attach` joins the live session (Ctrl-P Ctrl-Q to leave it
+
-running).
+### Talking to it
+
+Two channels, both live while it works:
+
+* **`./sylph-agent remote`** prints a `https://claude.ai/code/session_…` link.
+  `loose` starts Claude Code with `--remote-control`, so the session registers
+  with your account and you can chat with it from claude.ai or your phone —
+  which is the point of a detached run. Disable with `SYLPH_REMOTE=0`, rename
+  with `SYLPH_REMOTE_NAME`.
+
+  Registration takes a minute or two after launch, so `remote` waits for it
+  rather than reporting "not found" to what is really "not yet".
+
+* **`./sylph-agent attach`** joins the container's own terminal. Type to talk to
+  it; **Ctrl-P Ctrl-Q** detaches and leaves it running. Do not press Ctrl-C —
+  that goes to the agent.
+
+The pty is forced to 200×50 (`stty_init` in `bin/claude-autonomous`). A detached
+`docker run -t` is 80×24, and Claude Code hard-wraps to the terminal width,
+which truncated the Remote Control URL to `…/session_01…` in the one place you
+need to read it — and made `docker logs` almost unreadable besides.
 
 **It cannot push.** No git credentials are mounted, deliberately: a human
 reviews before anything leaves the box. Review with

docker/agent/bin/claude-autonomous

@@ -28,6 +28,12 @@
 set timeout 90
 log_user 1
 
+# Give the pty a wide, tall geometry. A detached `docker run -t` defaults to
+# 80x24, and Claude Code hard-wraps to the terminal width — which truncates the
+# Remote Control URL to "https://claude.ai/code/session_01…" in the one place
+# you need to read it, and makes `docker logs` nearly unusable generally.
+set stty_init "rows 50 cols 200"
+
 set answered_theme 0
 set answered_trust 0
 set answered_bypass 0

docker/agent/entrypoint.sh

@@ -115,6 +115,15 @@ if [ "${SYLPH_AUTONOMOUS:-0}" = "1" ]; then
   fi
   # The flag the user asked for. It is refused under root, which is why this
   # image runs as `agent`.
+  # Remote Control registers the session with your account so you can chat with
+  # the agent from claude.ai or your phone — the point of a detached run being
+  # that you are not sitting in front of it. The name is passed EXPLICITLY: the
+  # flag's value is optional, so a bare `--remote-control` would swallow the
+  # /loop prompt that follows as the session name.
+  if [ "${SYLPH_REMOTE:-1}" != "0" ]; then
+    set -- --remote-control "${SYLPH_REMOTE_NAME:-sylpheed-agent}" "$@"
+    log "Remote Control enabled as '${SYLPH_REMOTE_NAME:-sylpheed-agent}'"
+  fi
   # claude-autonomous wraps `claude --dangerously-skip-permissions` in a pty and
   # answers the one-time first-run gates. The Bypass Permissions disclaimer in
   # particular has no config key that skips it, so unattended it hangs forever.

docker/agent/sylph-agent

@@ -9,6 +9,7 @@
 #   ./sylph-agent agent [prompt]   Claude Code, --dangerously-skip-permissions
 #   ./sylph-agent loose [task]     turn it loose: detached, /loop, self-paced
 #   ./sylph-agent logs [-f]        what the loose agent is doing
+#   ./sylph-agent remote           print the Remote Control link (chat from anywhere)
 #   ./sylph-agent attach           attach to the loose agent's session
 #   ./sylph-agent run <cmd...>     one-shot command
 #   ./sylph-agent stop             stop it
@@ -18,6 +19,8 @@
 #   SYLPH_CLAUDE_HOME  host dir mounted as the agent's ~/.claude
 #                      (default: $HOME/.claude — shares auth AND memory with you)
 #   SYLPH_VULKAN=sw    force software Vulkan (lavapipe) even if /dev/dri exists
+#   SYLPH_REMOTE=0     do NOT enable Remote Control (default: enabled for `loose`)
+#   SYLPH_REMOTE_NAME  Remote Control session name (default: sylpheed-agent)
 #   SYLPH_CPUS / SYLPH_MEM_GB   override the computed half
 set -euo pipefail
 
@@ -124,6 +127,8 @@ docker_args() {
 
   [ -n "${ANTHROPIC_API_KEY:-}" ] && _out+=(-e "ANTHROPIC_API_KEY=$ANTHROPIC_API_KEY")
   [ -n "${SYLPH_VULKAN:-}" ]      && _out+=(-e "SYLPH_VULKAN=$SYLPH_VULKAN")
+  [ -n "${SYLPH_REMOTE:-}" ]      && _out+=(-e "SYLPH_REMOTE=$SYLPH_REMOTE")
+  [ -n "${SYLPH_REMOTE_NAME:-}" ] && _out+=(-e "SYLPH_REMOTE_NAME=$SYLPH_REMOTE_NAME")
   [ -n "${SYLPH_ISO:-}" ]         && _out+=(-e "SYLPH_ISO=$SYLPH_ISO")
 
   # ── GPU ──
@@ -196,8 +201,9 @@ case "${1:-}" in
     docker run -d -i -t "${ARGS[@]}" "$IMAGE" "/loop ${INTERVAL:+$INTERVAL }$TASK" >/dev/null
     echo
     echo "    running detached as '$NAME'."
+    echo "      ./sylph-agent remote      link to chat with it from anywhere"
     echo "      ./sylph-agent logs -f     follow it"
-    echo "      ./sylph-agent attach      attach to the session (Ctrl-P Ctrl-Q to detach)"
+    echo "      ./sylph-agent attach      chat with it locally (Ctrl-P Ctrl-Q to leave it running)"
     echo "      ./sylph-agent stop        stop it"
     echo
     echo "    It commits to auto/* branches and cannot push — no git credentials"
@@ -205,7 +211,35 @@ case "${1:-}" in
     ;;
 
   logs)   shift; exec docker logs "$@" "$NAME" ;;
-  attach) exec docker attach "$NAME" ;;
+
+  remote)
+    # Fish the Remote Control link out of the session's own output. Claude Code
+    # prints it once, when the session registers with your account — which takes
+    # a minute or two after launch, so this waits rather than answering "not
+    # found" to a question that is really "not yet".
+    printf 'waiting for the session to register' >&2
+    for i in $(seq 1 90); do
+      url=$(docker logs "$NAME" 2>&1 \
+            | sed 's/\x1b\[[0-9;]*[a-zA-Z]//g; s/\r//g' \
+            | grep -oE 'https://claude\.ai/code/[A-Za-z0-9_-]+' | tail -1)
+      if [ -n "${url:-}" ]; then
+        printf '\n' >&2
+        echo "$url"
+        exit 0
+      fi
+      docker ps -q -f "name=$NAME" | grep -q . || {
+        printf '\n' >&2
+        echo "container is not running — start it with: ./sylph-agent loose" >&2
+        exit 1
+      }
+      printf '.' >&2
+      sleep 4
+    done
+    printf '\n' >&2
+    echo "no Remote Control URL after 6 minutes." >&2
+    echo "  Launched with SYLPH_REMOTE=0? Or check: ./sylph-agent logs | tail" >&2
+    exit 1
+    ;;
 
   shell|agent|run)
     mode=$1; shift