fix(opencode): use inference.tinfoil.sh + attach TUI + NO_COLOR

Three fixes discovered during first live run:
- inference host is inference.tinfoil.sh not api.tinfoil.sh (control plane
  only serves /v1/models, not /v1/chat/completions)
- opencode run exits after one turn; switch to opencode attach for the
  persistent TUI, then ping_session sends the kickoff prompt
- NO_COLOR=1 suppresses the first-run interactive theme picker

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

cc-ci-plan/launch.py

@@ -205,10 +205,12 @@ def start_agent(role, session, workdir):
         cmd = f"{CLAUDE_BIN} {rc} {model_flag} {CLAUDE_FLAGS} \"$(cat '{kf}')\""
         log(f"starting {session} (backend=claude, phase={pid}, plan={plan}, model={LOOP_MODEL or 'default'})")
     elif BACKEND == "opencode":
+        # `opencode attach` is the persistent TUI (stays alive in tmux, like the claude TUI).
+        # We attach to the shared server, then send the kickoff message via tmux send-keys.
+        # The server stores the session by title; NO_COLOR=1 skips the first-run theme picker.
         cmd = (
             f"set -a; . /srv/cc-ci/.testenv; set +a; "
-            f"{OPENCODE_BIN} {model_flag} run --attach '{OPENCODE_SERVER}' "
-            f"--title '{session}' \"$(cat '{kf}')\""
+            f"NO_COLOR=1 {OPENCODE_BIN} {model_flag} attach '{OPENCODE_SERVER}'"
         )
         log(f"starting {session} (backend=opencode, phase={pid}, model={LOOP_MODEL or 'default'})")
         log(f"  visible at http://oc.commoninternet.net (tailnet only)")
@@ -218,6 +220,12 @@ def start_agent(role, session, workdir):
     subprocess.run(["tmux", "new-session", "-d", "-s", session, "-c", workdir, cmd])
     pipe_to_log(session, f"{LOG_DIR}/{session}.log")
 
+    # opencode: send the kickoff prompt once the TUI is ready (give it a moment to connect).
+    if BACKEND == "opencode":
+        time.sleep(4)
+        kickoff_text = kf.read_text().strip()
+        ping_session(session, kickoff_text)
+
 def start_loops():
     start_agent("builder",   BUILDER_SESSION, BUILDER_DIR)
     start_agent("adversary", ADV_SESSION,     ADV_DIR)