feat(sp24): align CLAUDE.md + REQUIREMENTS.md + ARCHITECTURE.md with auth work + AUTH_DISABLED WARNING

Replaces every stale 'no auth' / 'no authentication' / 'no second party to
authenticate' claim in the three top-level docs with the v1 posture: the
auth boundary is HTTP (bcrypt + HttpOnly session cookie; first admin
bootstrapped from CYCLONE_ADMIN_USERNAME + CYCLONE_ADMIN_PASSWORD env
vars); the file-system posture (SQLCipher at rest, macOS Keychain) is
unchanged; the threat model is still a stolen/imaged drive.

Closes requirements §11 R-1 (was Open; now Closed by SP24 — auth shipped
via the origin/main merge on 2026-06-23, SP24 reconciled the docs).

Also:
- backend/src/cyclone/__main__.py — emit WARNING when AUTH_DISABLED is
  True at boot so a misconfigured production deploy fails loudly
- §6.1 migrations table in ARCHITECTURE.md — list 0013 (auth_users_and_
  sessions) and 0014 (audit_log_user_id) with the renumbering note
- §4.2 module map — add the cyclone.auth.* package
- Three skills addenda: cyclone-tests (AUTH_DISABLED conftest bypass is
  mandatory context), cyclone-api-router (every router needs
  Depends(matrix_gate)), cyclone-spec (spec template threat-model is now
  auth-aware)

This also tracks CLAUDE.md in git for the first time (was previously
untracked; the SP24 doc updates are in scope for the increment).

Spec: docs/superpowers/specs/2026-06-23-cyclone-auth-posture-alignment-design.md
Plan: docs/superpowers/plans/2026-06-23-cyclone-auth-posture-alignment.md

.superpowers/skills/cyclone-api-router/SKILL.md

@@ -19,6 +19,10 @@ content negotiation + `tail_events`), and ~30 routes still inlined
 in `backend/src/cyclone/api.py`. The next refactor target is the
 parse endpoints.
 
+## Auth gate (SP24)
+
+Every router declared in `backend/src/cyclone/api_routers/` **must** carry `dependencies=[Depends(matrix_gate)]` at the `APIRouter(...)` declaration — not on each individual endpoint. The gate lives at `backend/src/cyclone/auth/deps.py:107` and the role matrix is at `backend/src/cyclone/auth/permissions.py`. The roles are `admin / user / viewer`; `matrix_gate` returns 401 when there's no session and 403 when the role is below the endpoint's required role. When `AUTH_DISABLED` is True (conftest autouse fixture flips it; `CYCLONE_AUTH_DISABLED=1` in prod-by-mistake), the gate short-circuits to a synthetic admin — see the SP24 spec for the threat-model implications. New routers get the gate by default; the auth-aware convention is `router = APIRouter(dependencies=[Depends(matrix_gate)])`.
+
 ## When to use
 
 - **Adding an endpoint.** You're adding a new GET / POST handler —