docs: address Codex review on README (EP-1 fail-open, CC0, tests)

[kaizencycle]

Mobius PR — Cycle

• Cycle: C-367
• Type: Docs
• Primary Area(s): docs
• Pulse Attached: ⬜

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1. Summary

Follow-up to #19 addressing three Codex review items on the README rewrite.

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2. Codex fixes

Review	Fix
P2 — EP-1 fail-open	Tier table documents PASS_WITH_BACKFILL on EP-1 vs QUARANTINE/FAIL_CLOSED on EP-2/EP-3; branch-protection caveat added
P2 — License mismatch	Badge, Contributing, and License sections aligned to CC0-1.0 (matches LICENSE + package.json)
P2 — Test commands	Restored node test/classify.test.mjs and node test/policy-ref.test.mjs (Action-specific; npm test skips these)

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3. Tests

• node test/classify.test.mjs — 11/11 pass
• node test/policy-ref.test.mjs — 9/9 pass

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Intent Publication

epicon_id: EPICON_C-367_DOCS_readme-codex-fixes_v1
ledger_id: kaizencycle
scope: docs
mode: normal
issued_at: 2026-07-15T00:00:00Z
expires_at: 2026-10-13T00:00:00Z
justification:
  VALUES INVOKED: integrity, transparency, accuracy
  REASONING: Codex review caught three README inaccuracies — overstated
    fail-closed guarantee, AGPL vs CC0 drift, and npm test not covering
    shipped Action tests. Patch aligns docs with runtime behavior.
  ANCHORS:
    - packages/guard-core/src/index.mjs (shouldFailCheck, PASS_WITH_BACKFILL)
    - LICENSE, package.json (CC0-1.0)
    - Codex review on PR #19
  BOUNDARIES: README.md only
  COUNTERFACTUAL: If tier semantics change in guard-core, update README table
counterfactuals:
  - If license strategy reverts to AGPL, update LICENSE + package.json + README together

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"We heal as we walk." — Mobius Substrate