Fix: child-config autoentities fails validation with "No entities found" when using data-source-files

[Copilot]

Why make this change?

• Closes [Bug]: autoentities in a child configuration file (referenced via data-source-files) is not recognized — validation fails with "No entities found" #3655
• When a child config (referenced via data-source-files) uses autoentities instead of explicit entities, validation incorrectly fails with "No entities found". The same autoentities block works correctly in the top-level config. This contradicts documented behavior that states every config may satisfy the entities requirement via autoentities.

What is this change?

• Root cause: MsSqlMetadataProvider.GenerateAutoentitiesIntoEntities stores autoentity resolution counts only on the root (merged) RuntimeConfig.AutoentityResolutionCounts. But ValidateEntityPresence checks the child config's own AutoentityResolutionCounts, which is never populated — so the resolved entity count is always 0 for child configs.

• Fix (RuntimeConfigValidator.ValidateRootConfig): Before validating each child config, copy any missing resolution counts from the root config into the child config. This is a no-op when child counts are already populated (e.g. in unit tests that pre-populate them directly).

foreach (KeyValuePair<string, Autoentity> ae in childConfig.Autoentities)
{
    if (!childConfig.AutoentityResolutionCounts.ContainsKey(ae.Key)
        && runtimeConfig.AutoentityResolutionCounts.TryGetValue(ae.Key, out int count))
    {
        childConfig.AutoentityResolutionCounts[ae.Key] = count;
    }
}

How was this tested?

• Integration Tests
• Unit Tests
  • TestChildWithDataSourceAndAutoentitiesResolvingEntitiesIsValid: child config with only autoentities resolving >0 entities (counts stored on root only) passes validation — direct regression test for the bug.
  • TestRootAndChildBothWithAutoentitiesResolvingEntitiesIsValid: both root and child have autoentities, all counts on root, both pass validation.

Sample Request(s)

// dab-config.child.json — previously caused "No entities found" during `dab validate`
{
  "data-source": { "database-type": "mssql", "connection-string": "@env('CONN_B')" },
  "autoentities": {
    "def-b": {
      "patterns": { "name": "b_{object}", "include": [ "dbo.TableTwo" ] },
      "permissions": [ { "role": "anonymous", "actions": [ { "action": "read" } ] } ]
    }
  }
}

dab validate -c dab-config.json  # now passes when child uses autoentities

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