feat(posture): add deterministic feedback proposals

Assistant: codex
Assistant-Model: gpt-5.6-sol
Assistant-Session: 01a02929-244b-7391-b933-c04010e8eedb

tools/posture-feedback/README.md

@@ -0,0 +1,22 @@
+# Posture Feedback Evaluator
+
+This tool implements the proposal-only feedback boundary in
+`canon/standards/posture-feedback_v0.1.md`. It reads tenancy declarations and
+emits deterministic JSON. It never writes State Hub, edits a declaration,
+changes policy, or executes remediation.
+
+Evaluate the checked-in reference at an explicit time:
+
+```bash
+uv run tools/posture-feedback/posture_feedback.py \
+  --as-of 2026-08-23T12:00:00Z \
+  --horizon-days 14 \
+  --fail-on none \
+  examples/posture-feedback/expired-e2.yaml
+```
+
+Run tests:
+
+```bash
+uv run pytest tools/posture-feedback/tests
+```