v0.8 W63 — Historical metrics provider, retention and query contracts

[ammarheidari]

Status

ACTIVE — Slice 1 provider foundation COMPLETE / protected-main verified; Slice 2 retention/rollup/HA coordination ACTIVE.

Scope

• explicit historical metrics persistence provider interface;
• retention/downsampling/compaction policy;
• bounded time-range/query contracts;
• standalone vs HA provider semantics;
• migration/versioning/failover tests;
• no mandatory historical provider when operators need only live metrics.

Safety

• raw record payloads, connector secrets and raw query results are not metrics history;
• Kafka is not silently used as Kafdeck's metrics database;
• retention and query ranges have hard server ceilings;
• persistence outages produce explicit stale/partial/unavailable state rather than fabricated zeros.

Authority: scope #208; tracker #209; admitted W61 planning package.

Slice 1 — provider foundation COMPLETE

• canonical PR feat(history): establish W63 historical metrics provider core #232;
• final exact head: 62c0dbeef5f36ccb985c6a39a61d09de53a7841f;
• protected-main merge: b2eb6b25008eb1cbbe2359a0da97ee5abd4e6f5d;
• SQLite standalone + PostgreSQL standalone/HA provider configuration;
• idempotent numeric aggregate persistence;
• bounded query range/series/points/duration/concurrency;
• native SQLite deadline interruption;
• PostgreSQL advisory-lock migration serialization;
• pre-DDL schema-version validation;
• separate raw/rollup retention deletion contract;
• exact-head quality/dependency/v0.3/v0.4/v0.5-persistence/CodeQL/supply-chain: SUCCESS;
• fresh CODEOWNER approval and Codex exact-head review: CLEAN;
• protected-main quality #1574: SUCCESS;
• protected-main CodeQL #1416: SUCCESS.

Slice 2 — ACTIVE

Admitted next scope:

• deterministic rollup/downsampling worker;
• separate raw/rollup retention execution;
• bounded work per cycle/backlog;
• leases/fencing for HA workers;
• no raw deletion before eligible rollup evidence is durably committed;
• missing evidence remains missing/partial, never numeric zero;
• retention/downsampling/failover/lease-fencing tests;
• no consumer-history capability claim until query/capability adapter evidence exists.

W64 may proceed in parallel on live analytics/contracts, but historical trend/SLO paths remain dependent on stable Slice 2 rollup/retention semantics.