Implement the following plan:

# Consolidate buildQueries / Scope Transformation Logic

## Context

`pkg/metricstore/query.go` (InternalMetricStore) and `internal/metricstoreclient/cc-metric-store-queries.go` (CCMetricStore) both implement the `MetricDataRepository` interface. They contain nearly identical scope-transformation logic for building metric queries, but the code has diverged:

- **metricstoreclient** has the cleaner design: a standalone `buildScopeQueries()` function handling all transformations
- **metricstore** has the same logic inlined as a long if-chain inside `buildQueries()` and duplicated in `buildNodeQueries()`
- **metricstore is missing** the `MemoryDomain → Socket` transformation that metricstoreclient has
- Both packages duplicate scope string constants, `intToStringSlice`, and `sanitizeStats`

Goal: Extract shared scope-transformation logic, synchronize behavior, and eliminate duplication.

## Approach

Extract `BuildScopeQueries` as a shared exported function in `pkg/metricstore/` (since metricstoreclient already imports it). Return a package-independent intermediate type (`ScopeQueryResult`) that each package converts to its own `APIQuery` — this avoids coupling the two different `APIQuery` types (they differ in `Resolution` type: `int64` vs `int`, and internal has `ScaleFactor`).

## Steps

### 1. Create `pkg/metricstore/scopequery.go`

New file containing:

- **`ScopeQueryResult`** struct — intermediate type with fields: `Metric`, `Hostname`, `Aggregate`, `Type *string`, `TypeIds []string`, `Scope schema.MetricScope` (no Resolution — callers set it)
- **`BuildScopeQueries()`** — exported function ported from `metricstoreclient/buildScopeQueries()` (lines 257-517), returning `([]ScopeQueryResult, error)`. Returns empty slice for expected exceptions, error for unhandled cases
- **Scope string constants** — `HWThreadString`, `CoreString`, `MemoryDomainString`, `SocketString`, `AcceleratorString` (exported, move from both packages)
- **`IntToStringSlice()`** — exported, using the optimized buffer-reuse version from metricstore
- **`SanitizeStats(avg, min, max *schema.Float)`** — exported, using the metricstoreclient behavior (zero ALL if ANY is NaN)

### 2. Update `pkg/metricstore/query.go`

- Replace inline if-chain in `buildQueries()` (lines 317-534) with call to `BuildScopeQueries()`, converting each `ScopeQueryResult` → local `APIQuery` (adding `Resolution`)
- Replace inline if-chain in `buildNodeQueries()` (lines 1099-1316) with same pattern
- Delete local scope string constants, `intToStringSlice`, local `sanitizeStats`
- Update `sanitizeStats` calls in `LoadData`/`LoadScopedStats`/`LoadNodeData`/`LoadNodeListData` to use `SanitizeStats(&res.Avg, &res.Min, &res.Max)`
- Switch scope dedup from `map[schema.MetricScope]bool` to labeled-loop + slice (matches metricstoreclient, avoids allocation for typical 1-3 scopes)
- This **adds the missing MemoryDomain → Socket transformation** to the internal store

### 3. Update `internal/metricstoreclient/cc-metric-store-queries.go`

- Replace call to local `buildScopeQueries()` with `metricstore.BuildScopeQueries()`, converting each `ScopeQueryResult` → local `APIQuery` (adding `Resolution`)
- Delete local `buildScopeQueries()` function
- Delete local scope string constants and `intToStringSlice`
- Update `sanitizeStats` in `cc-metric-store.go` to call `metricstore.SanitizeStats()`

### 4. Add tests: `pkg/metricstore/scopequery_test.go`

Table-driven tests for `BuildScopeQueries` covering all transformation cases:
- Same-scope (HWThread→HWThread, Core→Core, Socket→Socket, Node→Node, etc.)
- Aggregation (HWThread→Core, HWThread→Socket, HWThread→Node, Core→Socket, Core→Node, etc.)
- Accelerator cases (Accelerator→Accelerator, Accelerator→Node)
- MemoryDomain cases including MemoryDomain→Socket
- Unhandled case returns error

## Files Modified

| File | Action |
|------|--------|
| `pkg/metricstore/scopequery.go` | **New** — shared types and functions |
| `pkg/metricstore/scopequery_test.go` | **New** — tests for BuildScopeQueries |
| `pkg/metricstore/query.go` | Refactor buildQueries/buildNodeQueries to use BuildScopeQueries; remove duplicated helpers |
| `internal/metricstoreclient/cc-metric-store-queries.go` | Replace local buildScopeQueries with shared; remove duplicated helpers |
| `internal/metricstoreclient/cc-metric-store.go` | Update sanitizeStats to use shared SanitizeStats |

## What is NOT shared (intentionally)

- **`APIQuery`/`APIMetricData` types** — different Resolution types, Data types, ScaleFactor field
- **`buildQueries`/`buildNodeQueries` themselves** — different topology access (caching vs inline), different receiver types
- **Load* result-processing functions** — depend on package-specific types and fetch mechanisms

## Verification

1. `go build ./...` — compile check
2. `go test ./pkg/metricstore/...` — existing + new scopequery tests
3. `go test ./internal/metricstoreclient/...` — compile check
4. `make test` — full test suite


If you need specific details from before exiting plan mode (like exact code snippets, error messages, or content you generated), read the full transcript at: /Users/jan/.claude/projects/-Users-jan-prg-ClusterCockpit-cc-backend/eec1fc87-d8f6-42f6-b296-d7a2f79af002.jsonl