feat(wp-0002): complete T07 — control loop on the live backup resource

The backup is procured and proven, so the loop runs on real evidence.

- data/actuals/2026-08.json: first real observation. database 0.6365 GB,
  stored 0.0066 GB over 8 objects, backup success 1/1, restore RTO 1.08 min.
  Five proxies null, each with a named owner in measurement_gaps.
- data/thresholds/platform-audit-storage.json + tools/thresholds.py: budget
  variance, abnormal growth, stale backup, unused commitment. Fail-closed —
  an unmeasured value is reported as unmeasured, never as within.
- financial_exchange.py gains a usage mode emitting technical_usage records to
  fin-hub, with measurement gaps carried through and no infrastructure amount:
  fin-hub owns the booked fact and a null is never sent as 0.00.
- observation schema 0.2 allows null cost and usage proxies; variance.py fails
  closed rather than reporting a 100% favourable variance on a missing amount.
- platform-audit-storage: ordered -> active, commissioned 2026-08-14, on
  operational fact rather than on the purchase.

The optimization case is now approved by the founder. That needed a schema
change: Host Europe never supplied written terms, so options gained
excluded/exclusion_reason. Previously an unevaluable alternative blocked its
case forever, leaving the record claiming no decision while the bucket was in
production. An excluded option keeps its unknowns and must say what would
bring it back.

August produces no variance and should not: the decision forecast starts at
2026-09, so August is a commissioning baseline. Threshold run is 2 within,
1 not applicable, 6 unmeasured, 0 breaches.

Also fixes a pre-existing test failure: reef-storage consumers_actual is now
rapp-postgres, which the assertion still expected to be empty.

136 tests pass.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

tools/optimization.py

@@ -64,6 +64,18 @@ def utilization_ratios(option: dict) -> dict:
 
 def compare_option(baseline: dict, alternative: dict) -> dict:
     """Compare one alternative against the baseline on the decision fields."""
+    if alternative.get("excluded"):
+        # The deciding authority set this option aside rather than wait for
+        # evidence that was not going to arrive. It no longer blocks the case,
+        # and the reason travels with the decision.
+        return {
+            "option_id": alternative["option_id"],
+            "label": alternative["label"],
+            "verdict": "excluded",
+            "exclusion_reason": alternative.get("exclusion_reason"),
+            "blocking_evidence": [],
+        }
+
     blocking = sorted(set(
         [f"baseline.{field}" for field in missing_fields(baseline)]
         + [f"{alternative['option_id']}.{field}" for field in missing_fields(alternative)]
@@ -150,6 +162,12 @@ def validate_case(case: dict) -> None:
     if len(set(option_ids)) != len(option_ids):
         raise ValueError("option identifiers must be unique within a case")
 
+    for alternative in case["alternatives"]:
+        if alternative.get("excluded") and not alternative.get("exclusion_reason"):
+            raise ValueError(
+                f"excluded option {alternative['option_id']} must record an exclusion_reason"
+            )
+
     report = evaluate(case)
     blocked = any(r["verdict"] == "blocked_on_evidence" for r in report["comparisons"])