fix(tracking): bind tariffs to source rate records

[kfallah]

Disposition

This branch is superseded and is not intended for merge. Exact head preserved: 51fac14. No branch was deleted.

[greptile-apps]

Greptile Summary

This PR binds each priced usage dimension to an exact, retained source rate record by introducing ProviderTariffBillingMeter and wiring per-record source evidence (locator, digest, rate IDs, effective date) through the catalog, provenance, and route models.

• Adds ProviderTariffBillingMeter to budget.py, bumps ProviderTariffRoute to schema v2 (requiring an ordered (input_tokens, output_tokens) meter pair), and bumps ProviderTariffProvenance to schema v3 to reflect the structural change.
• Replaces the single global _normalized_bedrock_source_snapshot_digest() / _AWS_BEDROCK_SOURCE_SNAPSHOT_DIGEST aggregate hash with per-record source coordinates and independently-pinned per-record content digests in _BEDROCK_CATALOG_RECORD_DIGESTS, verified at import time.
• Extends tests to assert rate IDs and billing-meter ordering in catalog snapshots, and adds parametrized validation tests for invalid meter configurations.

Confidence Score: 5/5

Safe to stack — the per-record integrity check runs at import time, the billing-meter ordering is enforced by both the static type and the model validator, and the tests cover drift, wrong count, and wrong order.

Every changed path is guarded: catalog records are content-hashed and verified at import, the new billing_meters field is statically typed as an exact 2-tuple and dynamically validated for (input, output) ordering, and the test suite asserts the full set of new provenance fields for each catalog entry. No gaps in the fail-closed logic were found.

No files require special attention.

Important Files Changed

Filename	Overview
wmh/tracking/budget.py	Introduces ProviderTariffBillingMeter (schema v1) with usage_dimension + rate_id; bumps ProviderTariffRoute to schema v2 with mandatory billing_meters exact-2-tuple; bumps ProviderTariffProvenance to schema v3. Ordering is enforced by model validator; type annotation enforces 2-element constraint statically.
wmh/tracking/tariffs.py	Replaces single aggregate catalog digest with per-record source coordinates (locator, digest, rate IDs, effective_on) in _BedrockCatalogRecord and independently pinned per-record content digests in _BEDROCK_CATALOG_RECORD_DIGESTS; integrity guard called at import time. No logic errors found.
wmh/tracking/tariffs_test.py	Adds integrity-guard tests for price-drift and record-set-drift, extends parametrized catalog tests to assert per-record source locator / digest / rate IDs / billing SKU, and adds billing-meter ordering validation tests covering wrong count and wrong order.
wmh/tracking/_testing.py	Adds billing_meters to synthetic_tariff_provenance so callers that use ProviderTariffRoute now supply the mandatory field; no issues.
wmh/tracking/init.py	Exports ProviderTariffBillingMeter from the tracking public API; change is additive and consistent with existing export pattern.

Sequence Diagram

%%{init: {'theme': 'neutral'}}%%
sequenceDiagram
    participant Import as Module Import
    participant VCI as _verify_bedrock_catalog_integrity
    participant Digest as _bedrock_catalog_record_digest
    participant Records as _BEDROCK_CATALOG_RECORDS
    participant Pins as _BEDROCK_CATALOG_RECORD_DIGESTS

    Import->>VCI: _verify_bedrock_catalog_integrity(_BEDROCK_CATALOG_RECORDS)
    VCI->>Records: iterate record.model keys
    VCI->>Pins: compare ordered keys
    alt set / order mismatch
        VCI-->>Import: RuntimeError("record set changed")
    end
    loop each record
        VCI->>Digest: _bedrock_catalog_record_digest(record)
        Digest->>Digest: "json.dumps(record.model_dump(mode="json"), sort_keys=True)"
        Digest->>Digest: sha256(encoded)
        Digest-->>VCI: "sha256:..."
        VCI->>Pins: lookup _BEDROCK_CATALOG_RECORD_DIGESTS[record.model]
        alt digest mismatch
            VCI-->>Import: "RuntimeError("record changed: {model}")"
        end
    end
    VCI-->>Import: OK

    Note over Import: Build _CATALOG from _BEDROCK_CATALOG_RECORDS

    participant Factory as ProviderTokenTariff.from_usd_per_million
    participant Route as ProviderTariffRoute
    participant Meter as ProviderTariffBillingMeter

    Import->>Factory: "_bedrock_tariff(record=record)"
    Factory->>Meter: "ProviderTariffBillingMeter(usage_dimension="input_tokens", rate_id=input_rate_id)"
    Factory->>Meter: "ProviderTariffBillingMeter(usage_dimension="output_tokens", rate_id=output_rate_id)"
    Factory->>Route: "ProviderTariffRoute(..., billing_meters=(input_meter, output_meter))"
    Route->>Route: validate ordering: input_tokens then output_tokens
    Route-->>Factory: frozen route
    Factory-->>Import: ProviderTokenTariff (immutable)

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%%{init: {'theme': 'base', 'themeVariables': {"darkMode": true, "background": "#0d1117", "primaryColor": "#21262d", "primaryTextColor": "#e6edf3", "primaryBorderColor": "#8b949e", "lineColor": "#8b949e", "textColor": "#e6edf3", "edgeLabelBackground": "#161b22", "actorBkg": "#21262d", "actorBorder": "#8b949e", "actorTextColor": "#e6edf3", "actorLineColor": "#8b949e", "signalColor": "#8b949e", "signalTextColor": "#e6edf3", "noteBkgColor": "#373320", "noteBorderColor": "#d4a72c", "noteTextColor": "#f0e6c0", "labelBoxBkgColor": "#21262d", "labelBoxBorderColor": "#8b949e", "labelTextColor": "#e6edf3", "loopTextColor": "#e6edf3", "activationBkgColor": "#30363d", "activationBorderColor": "#8b949e"}}}%%
sequenceDiagram
    participant Import as Module Import
    participant VCI as _verify_bedrock_catalog_integrity
    participant Digest as _bedrock_catalog_record_digest
    participant Records as _BEDROCK_CATALOG_RECORDS
    participant Pins as _BEDROCK_CATALOG_RECORD_DIGESTS

    Import->>VCI: _verify_bedrock_catalog_integrity(_BEDROCK_CATALOG_RECORDS)
    VCI->>Records: iterate record.model keys
    VCI->>Pins: compare ordered keys
    alt set / order mismatch
        VCI-->>Import: RuntimeError("record set changed")
    end
    loop each record
        VCI->>Digest: _bedrock_catalog_record_digest(record)
        Digest->>Digest: "json.dumps(record.model_dump(mode="json"), sort_keys=True)"
        Digest->>Digest: sha256(encoded)
        Digest-->>VCI: "sha256:..."
        VCI->>Pins: lookup _BEDROCK_CATALOG_RECORD_DIGESTS[record.model]
        alt digest mismatch
            VCI-->>Import: "RuntimeError("record changed: {model}")"
        end
    end
    VCI-->>Import: OK

    Note over Import: Build _CATALOG from _BEDROCK_CATALOG_RECORDS

    participant Factory as ProviderTokenTariff.from_usd_per_million
    participant Route as ProviderTariffRoute
    participant Meter as ProviderTariffBillingMeter

    Import->>Factory: "_bedrock_tariff(record=record)"
    Factory->>Meter: "ProviderTariffBillingMeter(usage_dimension="input_tokens", rate_id=input_rate_id)"
    Factory->>Meter: "ProviderTariffBillingMeter(usage_dimension="output_tokens", rate_id=output_rate_id)"
    Factory->>Route: "ProviderTariffRoute(..., billing_meters=(input_meter, output_meter))"
    Route->>Route: validate ordering: input_tokens then output_tokens
    Route-->>Factory: frozen route
    Factory-->>Import: ProviderTokenTariff (immutable)

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_{Reviews (5): Last reviewed commit: "refactor(tracking): type exact billing m..." | Re-trigger Greptile}

[kfallah]

Closing because this branch is superseded and is not intended for merge. Exact head preserved: 51fac14. No branch was deleted.