Merge branch 'worktree-agent-a63474e92b05425a5'

# Conflicts:
#	Cargo.lock
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tickets/013-dashboards-promql.md

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+# 013 — Dashboards: PromQL query support
+
+## Summary
+
+Support PromQL-style queries over declared metrics to derive dashboard
+visualizations, per the README's Dashboards section ("There should be support for
+promql queries to derive the visualisation").
+
+## Scope
+
+- Evaluate a useful PromQL subset (instant/range vector selection by metric name +
+  label matchers, at minimum; consider `rate()`/`sum()`/`avg()` aggregations as
+  stretch) against `Bucket` data ([003](003-metric-bucket-derivation.md)).
+- Decide whether to hand-roll the subset or bring in an existing PromQL parser
+  crate — document the choice.
+- New `EngineQuery` variant for PromQL evaluation, following the existing
+  single-owner-evaluates-in-place pattern.
+- API endpoint (e.g. `GET /api/query?promql=...`) returning a chart-ready series
+  format (labels + time-value pairs), shaped for bar/line/pie consumption by
+  [014](014-dashboards-ui.md).
+
+## Acceptance criteria
+
+- A basic instant/range query against a declared metric with a label matcher returns
+  correct series data against a seeded fixture.
+- Malformed PromQL returns a 4xx with a useful error.
+
+## Depends on
+
+- [004 — Metrics API](004-metrics-api.md)