cc-ci host: the orchestrator is an opencode agent; no Claude on the box; /secrets convention

Operator 2026-09-07 (evening): Claude sessions stay on notplants-orchestrator;
on the cc-ci host the orchestrator is an opencode agent (agents.toml:
opencode/glm-5.2) steered from https://oc.ci.commoninternet.net, next to the
upgrader/report sessions. claude-install and CLAUDE_BIN are gone from the
modules; launch-upgrader/report print the real UI URL; README "Operating the
orchestrator" rewritten and a "Weekly upgrade run" section added.

Secrets: only cc-ci's, under /secrets/files with runtime paths symlinked
(README §4 table), nothing from other projects — tangled key and the
tailscale line dropped from the host.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FqkQq3CDmFWcQ7u1LzoyRz

cc-ci-plan/agents.toml

@@ -53,8 +53,9 @@ log_dir = "/srv/cc-ci/.cc-ci-logs"
 [[agent]]
 name    = "orchestrator"       # tmux session: cc-ci-orchestrator
 kind    = "persistent"
-backend = "claude"             # operator 2026-09-07: Claude Code under remote-control so they can talk to it
-model   = "claude-fable-5-1"   # Fable 5.1
+backend = "opencode"           # operator 2026-09-07 (evening): NO Claude on the cc-ci host — the
+model   = "opencode/glm-5.2"   # orchestrator is an opencode agent, steered via the opencode web UI
+                               # (https://oc.ci.commoninternet.net). Claude sessions live on notplants-orchestrator.
 resume  = false                # opencode backend has no --resume equivalent (fresh session each launch)
 watch   = "heal"               # restart if dead / FATAL / backend-mismatch; never stall-reboot
 wake    = { interval = 3600, prompt_file = "ai-progress-monitor-prompt.txt" }