feat: Add DigestUpsertRequest and LockEntity models

- Introduced DigestUpsertRequest for handling digest upsert requests with properties like ChannelId, Recipient, DigestKey, Events, and CollectUntil.
- Created LockEntity to represent a lightweight distributed lock entry with properties such as Id, TenantId, Resource, Owner, ExpiresAt, and CreatedAt.

feat: Implement ILockRepository interface and LockRepository class

- Defined ILockRepository interface with methods for acquiring and releasing locks.
- Implemented LockRepository class with methods to try acquiring a lock and releasing it, using SQL for upsert operations.

feat: Add SurfaceManifestPointer record for manifest pointers

- Introduced SurfaceManifestPointer to represent a minimal pointer to a Surface.FS manifest associated with an image digest.

feat: Create PolicySimulationInputLock and related validation logic

- Added PolicySimulationInputLock record to describe policy simulation inputs and expected digests.
- Implemented validation logic for policy simulation inputs, including checks for digest drift and shadow mode requirements.

test: Add unit tests for ReplayVerificationService and ReplayVerifier

- Created ReplayVerificationServiceTests to validate the behavior of the ReplayVerificationService under various scenarios.
- Developed ReplayVerifierTests to ensure the correctness of the ReplayVerifier logic.

test: Implement PolicySimulationInputLockValidatorTests

- Added tests for PolicySimulationInputLockValidator to verify the validation logic against expected inputs and conditions.

chore: Add cosign key example and signing scripts

- Included a placeholder cosign key example for development purposes.
- Added a script for signing Signals artifacts using cosign with support for both v2 and v3.

chore: Create script for uploading evidence to the evidence locker

- Developed a script to upload evidence to the evidence locker, ensuring required environment variables are set.

scripts/replay/verify-policy-sim-lock.sh

@@ -0,0 +1,88 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Offline verifier for policy-sim inputs lock (PS1–PS10 remediation).
+# Usage: verify-policy-sim-lock.sh lock.json --policy path --graph path --sbom path --time-anchor path --dataset path [--max-age-hours 24]
+
+usage() {
+  echo "Usage: $0 lock.json --policy <file> --graph <file> --sbom <file> --time-anchor <file> --dataset <file> [--max-age-hours <n>]" >&2
+  exit 2
+}
+
+[[ $# -lt 11 ]] && usage
+
+lock=""
+policy=""
+graph=""
+sbom=""
+time_anchor=""
+dataset=""
+max_age_hours=0
+
+while [[ $# -gt 0 ]]; do
+  case "$1" in
+    --policy) policy=${2:-}; shift ;;
+    --graph) graph=${2:-}; shift ;;
+    --sbom) sbom=${2:-}; shift ;;
+    --time-anchor) time_anchor=${2:-}; shift ;;
+    --dataset) dataset=${2:-}; shift ;;
+    --max-age-hours) max_age_hours=${2:-0}; shift ;;
+    *) if [[ -z "$lock" ]]; then lock=$1; else usage; fi ;;
+  esac
+  shift
+done
+
+[[ -z "$lock" || -z "$policy" || -z "$graph" || -z "$sbom" || -z "$time_anchor" || -z "$dataset" ]] && usage
+
+require() { command -v "$1" >/dev/null || { echo "$1 is required" >&2; exit 2; }; }
+require jq
+require sha256sum
+
+calc_sha() { sha256sum "$1" | awk '{print $1}'; }
+
+lock_policy=$(jq -r '.policyBundleSha256' "$lock")
+lock_graph=$(jq -r '.graphSha256' "$lock")
+lock_sbom=$(jq -r '.sbomSha256' "$lock")
+lock_anchor=$(jq -r '.timeAnchorSha256' "$lock")
+lock_dataset=$(jq -r '.datasetSha256' "$lock")
+lock_shadow=$(jq -r '.shadowIsolation' "$lock")
+lock_scopes=$(jq -r '.requiredScopes[]?' "$lock" | tr '\n' ' ')
+lock_generated=$(jq -r '.generatedAt' "$lock")
+
+sha_ok() {
+  [[ $1 =~ ^[A-Fa-f0-9]{64}$ ]]
+}
+
+for h in "$lock_policy" "$lock_graph" "$lock_sbom" "$lock_anchor" "$lock_dataset"; do
+  sha_ok "$h" || { echo "invalid digest format: $h" >&2; exit 3; }
+done
+
+[[ "$lock_shadow" == "true" ]] || { echo "shadowIsolation must be true" >&2; exit 5; }
+if ! grep -qi "policy:simulate:shadow" <<< "$lock_scopes"; then
+  echo "requiredScopes missing policy:simulate:shadow" >&2; exit 5;
+fi
+
+[[ "$lock_policy" == "$(calc_sha "$policy")" ]] || { echo "policy digest mismatch" >&2; exit 3; }
+[[ "$lock_graph" == "$(calc_sha "$graph")" ]] || { echo "graph digest mismatch" >&2; exit 3; }
+[[ "$lock_sbom" == "$(calc_sha "$sbom")" ]] || { echo "sbom digest mismatch" >&2; exit 3; }
+[[ "$lock_anchor" == "$(calc_sha "$time_anchor")" ]] || { echo "time anchor digest mismatch" >&2; exit 3; }
+[[ "$lock_dataset" == "$(calc_sha "$dataset")" ]] || { echo "dataset digest mismatch" >&2; exit 3; }
+
+if [[ $max_age_hours -gt 0 ]]; then
+  now=$(date -u +"%Y-%m-%dT%H:%M:%SZ")
+  age_hours=$(python3 - <<'PY'
+import sys,datetime
+lock=sys.argv[1].replace('Z','+00:00')
+now=sys.argv[2].replace('Z','+00:00')
+l=datetime.datetime.fromisoformat(lock)
+n=datetime.datetime.fromisoformat(now)
+print((n-l).total_seconds()/3600)
+PY
+"$lock_generated" "$now")
+  if (( $(printf '%.0f' "$age_hours") > max_age_hours )); then
+    echo "lock stale: ${age_hours}h > ${max_age_hours}h" >&2
+    exit 4
+  fi
+fi
+
+echo "policy-sim lock verified (shadow mode enforced)."