P2 codify triage playbook into solo-mars-cc.md (auth-gate first) before any solo alert duty (bs-mr8o7w73qz4)

Codify the benign-vs-real alert triage playbook into solo-mars-cc.md per closed brainstorm bs-mr8o7w73qz4, hardest-first. Entry 1 HARD: auth-gate 401/403 -> gate-correct=close-with-evidence (caller+why-denied, NEVER relax the gate) / legit-user-blocked=fix calling path. Below it the soft layer (scanner-probe->silent, systemBanner-timeout->benign-blip, PKCE-missing->benign-env, appEvents-WI->verify-live-first, no-profile->correct-state), each {signature->default->escalate-if->source-memory link}. Prereq for P3 backtest + P4 fly-solo re-enable. solo-mars = single-writer; PM/audit propose by DM.