Add samples for all transforms to the samples project, fixes #2237

[bamaer]

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[mattcasters]

[bug] Database impact input only analyses a pipeline when filename-field names a field that holds a pipeline or workflow path. This transform never sets that property, and the only incoming value is the literal sample-value, so DbImpactInput skips the row and writes nothing. The note says the sample collects impact, but a run produces no impact rows.

Suggestion: Add a filename field, for example ${PROJECT_HOME}/transforms/table-exists.hpl, and set <filename-field> to that field.

[bamaer]

Fixed. A Get variables transform now builds ${PROJECT_HOME}/transforms/tableoutput-basic.hpl into a filename field, and filename-field points at that field. I didn't use a data grid: DbImpactInput doesn't resolve variables in the filename value, so the literal ${PROJECT_HOME} path failed. The sample now returns 5 impact rows.

[mattcasters]

[bug] GetServerStatus only reads server_field after an input row arrives. This pipeline has no upstream transform, so processRow() gets a null row and finishes before it looks up serverName. The note says a reachable Hop server is required, but nothing is queried, and the sample is not on the integration-test ignore list.

Suggestion: Feed a server name from a data grid, and either ship a matching Hop-server metadata object or add get-server-status.hpl to the ignore list so a missing server does not fail read-samples-build-hop-run.

[bamaer]

Fixed. A data grid feeds serverName = local-hop-server, and the sample ships metadata/server/local-hop-server.json (localhost:8080, cluster/cluster). When no server is running, the sample still finishes cleanly with available = N and the reason in errorMessage, so it stays off the ignore list.

[mattcasters]

[suggestion] The note says the child rows are passed back as a data stream, but execution_result_target_transform is empty and there is no output-rows source transform. PipelineExecutor only copies child rows and execution statistics when those targets are set, so pipeline-executor-child.hpl runs and its child_value row is discarded.

Suggestion: Hop the executor to a downstream transform, set the execution-result target, and set the output-rows source to child data. Otherwise change the note so it does not claim the child rows are returned.

[bamaer]

Fixed. The child now ends with Copy rows to result. In the parent, the execution results go to execution results and the result rows (child_value) go to child rows, both Dummy transforms. "Output rows source" isn't a parent setting: result_rows_target_transform only receives what the child copies to the result.

[mattcasters]

[nit] structured-extract-basic.hpl is already in this ignore list ("requires an AI provider named ollama-local"). This second row only repeats the exclusion with a slightly different reason.

Suggestion: Drop the duplicate row.

[bamaer]

Removed the duplicate row.