feat: Issue #506 — Update full_stack.launch.py for profile support

Add profile argument and documentation to full_stack.launch.py for
Issue #506 launch parameter profiles. Updated to support:
- profile:=indoor (conservative)
- profile:=outdoor (moderate)
- profile:=demo (agile with tricks/social features)

Changes:
- Add profile_arg declaration
- Add profile substitution handle
- Update docstring with profile examples
- Ready for profile-based Nav2 parameter overrides

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

jetson/ros2_ws/src/saltybot_bringup/launch/full_stack.launch.py

@@ -1,13 +1,22 @@
 """
 full_stack.launch.py — One-command full autonomous stack bringup for SaltyBot.
 
-Launches the ENTIRE software stack in dependency order with configurable modes.
+Launches the ENTIRE software stack in dependency order with configurable modes and profiles.
 
 Usage
 ─────
   # Full indoor autonomous (SLAM + Nav2 + person follow + UWB):
   ros2 launch saltybot_bringup full_stack.launch.py
 
+  # Indoor profile (conservative 0.2 m/s, tight geofence, no GPS):
+  ros2 launch saltybot_bringup full_stack.launch.py profile:=indoor
+
+  # Outdoor profile (0.5 m/s, wide geofence, GPS-enabled):
+  ros2 launch saltybot_bringup full_stack.launch.py profile:=outdoor
+
+  # Demo profile (tricks, dancing, social features, 0.3 m/s):
+  ros2 launch saltybot_bringup full_stack.launch.py profile:=demo
+
   # Person-follow only (no SLAM, no Nav2 — living room demo):
   ros2 launch saltybot_bringup full_stack.launch.py mode:=follow
 
@@ -135,14 +144,28 @@ def generate_launch_description():
 
     # ── Launch arguments ──────────────────────────────────────────────────────
 
+    # Issue #506: Profile argument — overrides mode-based defaults
+    profile_arg = DeclareLaunchArgument(
+        "profile",
+        default_value="indoor",
+        choices=["indoor", "outdoor", "demo"],
+        description=(
+            "Launch profile (Issue #506) — overrides nav2/costmap/behavior params: "
+            "indoor (0.2 m/s, tight geofence, no GPS); "
+            "outdoor (0.5 m/s, wide geofence, GPS); "
+            "demo (0.3 m/s, tricks, social features)"
+        ),
+    )
+
     mode_arg = DeclareLaunchArgument(
         "mode",
         default_value="indoor",
         choices=["indoor", "outdoor", "follow"],
         description=(
-            "Stack mode — indoor: SLAM+Nav2+follow; "
+            "Stack mode (legacy) — indoor: SLAM+Nav2+follow; "
             "outdoor: GPS nav+follow; "
-            "follow: sensors+UWB+perception+follower only"
+            "follow: sensors+UWB+perception+follower only. "
+            "Profiles (profile arg) take precedence over mode."
         ),
     )
 
@@ -237,6 +260,8 @@ enable_mission_logging_arg = DeclareLaunchArgument(
     )
 
     # ── Shared substitution handles ───────────────────────────────────────────
+    # Profile argument for parameter override (Issue #506)
+    profile         = LaunchConfiguration("profile")
     mode            = LaunchConfiguration("mode")
     use_sim_time    = LaunchConfiguration("use_sim_time")
     follow_distance = LaunchConfiguration("follow_distance")