launchers: default LOOP_TIER to 'go' — zen endpoint dead server-side, silently ate the 2026-09-18 weekly report

cc-ci-plan/launch-upgrader.py

@@ -44,11 +44,13 @@ WORKDIR = os.environ.get("UPGRADER_DIR",     "/srv/cc-ci")
 LOG_DIR = os.environ.get("LOG_DIR",          "/srv/cc-ci/.cc-ci-logs")
 
 # LOOP_BACKEND / LOOP_MODEL take precedence (unified control from the operator).
-# LOOP_TIER selects the OpenCode subscription: "zen" (default) or "go". Go hit a monthly
-# usage limit; ZEN is the working alternative. Set LOOP_TIER=go when the Go limit resets.
+# LOOP_TIER selects the OpenCode subscription: "go" (DEFAULT — the only tier with a key on
+# this host) or "zen" (opt-in on a host that has a ZEN key). ZEN models are DEAD here — the
+# endpoint errors server-side, and env loss in the tmux→agent→launch-report chain is exactly
+# how it silently ate the 2026-09-18 weekly report. Never default back to zen.
 # Only affects the opencode backend; claude ignores the tier.
 BACKEND = os.environ.get("LOOP_BACKEND", os.environ.get("UPGRADER_BACKEND", "opencode"))
-TIER = os.environ.get("LOOP_TIER", os.environ.get("UPGRADER_TIER", "zen"))
+TIER = os.environ.get("LOOP_TIER", os.environ.get("UPGRADER_TIER", "go"))
 _TIER_CFG = {
     "go":  {"model": "opencode-go/glm-5.2", "endpoint": "https://opencode.ai/zen/go/v1/chat/completions",
             "auth": "opencode-go", "label": "OpenCode Go"},
@@ -58,7 +60,7 @@ _TIER_CFG = {
 if BACKEND == "opencode" and TIER not in _TIER_CFG:
     print(f"[upgrader] ERROR: unknown LOOP_TIER '{TIER}' — use 'go' or 'zen'", flush=True)
     sys.exit(1)
-_tier = _TIER_CFG.get(TIER, _TIER_CFG["zen"])
+_tier = _TIER_CFG.get(TIER, _TIER_CFG["go"])
 _DEFAULT_MODEL = _tier["model"] if BACKEND == "opencode" else "sonnet"
 MODEL   = os.environ.get("LOOP_MODEL",   os.environ.get("UPGRADER_MODEL",   _DEFAULT_MODEL))