feat(pi): pi-automaton.sh startup context printer for Pi Dev

Pi Dev doesn't auto-load automaton's system prompt (unlike opencode),
so the agent has no awareness of tasks, phases, or status.py commands.
This bridges that gap:

- scripts/pi-automaton.sh: NEW — detects scope (framework/project),
  reads active tasks, default model, config snippet, AGENTS.md rules,
  and prints a formatted context block the user pastes as their first
  message to the Pi Dev agent. Does NOT launch pi.
- scripts/register-guards.sh: EXTENDED — after Pi Dev guard install,
  offers to symlink pi-automaton.sh to ~/bin/pi-automaton
  (interactive prompt only when stdin is a terminal).
- README.md: added 'Using Pi Dev with automaton' FAQ subsection
  documenting the context printer workflow.

scripts/register-guards.sh

@@ -66,6 +66,31 @@ if command -v pi &>/dev/null; then
         INSTALLED_PI=true
         echo "Pi Dev: installed"
     fi
+    # Offer pi-automaton startup wrapper
+    PI_WRAPPER="$FRAMEWORK_DIR/scripts/pi-automaton.sh"
+    if [ -f "$PI_WRAPPER" ]; then
+        echo ""
+        echo "Pi Dev context wrapper available at:"
+        echo "  $PI_WRAPPER"
+        echo ""
+        echo "Before starting a Pi Dev session, run this script to print"
+        echo "automaton project context that you can paste as your first message."
+        echo ""
+        echo "  bash ~/.automaton/scripts/pi-automaton.sh"
+        echo ""
+        # Only prompt interactively if stdin is a terminal
+        BIN_DIR="$HOME/bin"
+        if [ -t 0 ] && [ ! -f "$BIN_DIR/pi-automaton" ]; then
+            echo -n "Symlink to ~/bin/pi-automaton for easier access? [Y/n] "
+            read -r REPLY
+            if [ -z "$REPLY" ] || [ "$REPLY" = "y" ] || [ "$REPLY" = "Y" ]; then
+                mkdir -p "$BIN_DIR"
+                ln -sf "$PI_WRAPPER" "$BIN_DIR/pi-automaton"
+                echo "  Created $BIN_DIR/pi-automaton → $PI_WRAPPER"
+                echo "  (ensure ~/bin is in your PATH)"
+            fi
+        fi
+    fi
 else
     echo "Pi Dev: not detected (pi not in PATH)"
 fi