Loki Mode

Council trust-config fixes + zero-friction adoption

• COUNCIL_THRESHOLD now honored (tighten-only, bash route) (autonomy/completion-council.sh):
  the operator's LOKI_COUNCIL_THRESHOLD was silently ignored by the vote (a
  hardcoded 2/3 formula was used), so setting a stricter threshold was a no-op
  while the logs claimed it was active. The effective threshold is now
  max(2/3-majority floor, operator threshold), clamped to council size: an
  operator can TIGHTEN the completion gate but never weaken it below the safety
  floor. Shared _council_effective_threshold helper used at all three vote
  sites (council_vote, council_aggregate_votes, council_evaluate). This covers
  the live bash route; the dormant Bun runner council (not yet wired into the
  completion-decision path) carries the same latent gap and is a tracked
  follow-up.

• COUNCIL_SIZE guarded (autonomy/completion-council.sh): a non-positive or
  non-numeric LOKI_COUNCIL_SIZE made the 2/3 floor 0 and could let an empty
  council "approve" by default; it now falls back to a sane size (3).

• Fallback completion signal always valid JSON (autonomy/run.sh): the
  COMPLETION_REQUESTED fallback synthesized its payload with a bare redirect that
  truncated the file before python ran; a python crash mid-write could leave an
  empty/partial file that downstream json.loads silently dropped. It now writes
  to a temp file and atomically renames, with a hand-built valid-JSON fallback
  when python is unavailable.

• Zero-friction: catch "Claude installed but not logged in" in preflight
  (autonomy/run.sh): when claude is the provider, no ANTHROPIC_API_KEY, and
  no credentials file exists (never logged in), the build used to enter, make a
  failing call, and 401 - forcing the user to run loki why. It now fails fast
  with the same one-step claude login fix (opt out: LOKI_SKIP_AUTH_PREFLIGHT=1).

• Docs: floating Docker tag (README.md): the raw-docker quickstart pinned a
  stale :7.58.1; now uses :latest so the copy-paste pulls the current image.

  Found by wave-6 adversarial hunt + a zero-friction adoption analysis.