Fix /chat handoff and Morph launcher onboarding

README.md

@@ -122,7 +122,7 @@ If you want the plain-language version first, read the [Start Here guide](websit
 ```
 gauss                         # Launch the CLI
 /start                        # Show the first steps and turn on plain-language chat
-/chat                         # Ask a plain-language question first
+/chat                         # Open the configured managed backend chat session first
 /project create ~/my-project --template-source <template-or-git-url>
 /prove 1+1=2                  # Spawn a proving agent
 /swarm                        # See running agents
@@ -134,7 +134,7 @@ If you already have a Lean project:
 cd ~/my-lean-project
 gauss
 /start                        # Optional: turn on onboarding mode first
-/chat                         # Optional: ask questions before choosing a workflow
+/chat                         # Optional: open the configured managed backend chat session before choosing a workflow
 /project init                 # Register it as a Gauss project
 /prove                        # Start proving
 ```

agent/prompt_builder.py

@@ -67,8 +67,9 @@ def _scan_context_content(content: str, filename: str) -> str:
     "a general self-summary unless the user explicitly asks. When asked who you "
     "are, answer briefly and return to the work. "
     "When the user is trying to use Open Gauss itself or seems unsure how to "
-    "start, give them the lowest-friction path first: point them to /start or /chat if "
-    "they want orientation or plain-language help, and point them to /project "
+    "start, give them the lowest-friction path first: point them to /start if "
+    "they want inline orientation or plain-language help, point them to /chat "
+    "if they want a managed Claude Code or Codex chat session, and point them to /project "
     "when they are ready to create or activate a Gauss project. After that, "
     "tell them to run /prove, /autoprove, /formalize, or /autoformalize "
     "followed by a natural-language instruction, for example /autoprove The "