Improve linger/timeout validation error message with aliases

[MXLange]

Improves the producer configuration validation error message by explicitly showing alias mappings.

Previously, the error only said:

• message.timeout.ms must be greater than linger.ms

This can be confusing when users configure equivalent properties with different names.

This change updates the message to:

• delivery.timeout.ms (alias message.timeout.ms) must be greater than linger.ms (alias queue.buffering.max.ms)

Impact:

• clearer diagnostics
• easier troubleshooting for mixed alias usage
• no behavioral change (message-only improvement)

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[Copilot]

Pull request overview

This pull request aims to improve the clarity of producer configuration validation error messages by adding alias information. The changes update two error message strings that are displayed when message.timeout.ms is not greater than linger.ms.

Changes:

• Enhanced validation error messages in rd_kafka_conf_finalize() and rd_kafka_topic_conf_finalize() to show both property names and their aliases
• No functional or behavioral changes—purely a message improvement

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[Copilot]

The alias relationships in this error message are backwards. According to the configuration definitions:

• message.timeout.ms (line 1730) is the primary/canonical property, and delivery.timeout.ms (line 1742) is an alias for it
• queue.buffering.max.ms (line 1579) is the primary/canonical property, and linger.ms (line 1588) is an alias for it

The error message should say:

• message.timeout.ms (alias delivery.timeout.ms) must be greater than queue.buffering.max.ms (alias linger.ms)

This would correctly show the canonical property first, followed by its alias in parentheses.

Suggested change

	return "`delivery.timeout.ms` "
	"(alias "
	"`message.timeout.ms`) "
	"must be greater than "
	"`linger.ms` "
	"(alias "
	"`queue.buffering.max.ms`)";
	return "`message.timeout.ms` "
	"(alias "
	"`delivery.timeout.ms`) "
	"must be greater than "
	"`queue.buffering.max.ms` "
	"(alias "
	"`linger.ms`)";

[Copilot]

The alias relationships in this error message are backwards. According to the configuration definitions:

• message.timeout.ms (line 1730) is the primary/canonical property, and delivery.timeout.ms (line 1742) is an alias for it
• queue.buffering.max.ms (line 1579) is the primary/canonical property, and linger.ms (line 1588) is an alias for it

The error message should say:

• message.timeout.ms (alias delivery.timeout.ms) must be greater than queue.buffering.max.ms (alias linger.ms)

This would correctly show the canonical property first, followed by its alias in parentheses.

Suggested change

	return "`delivery.timeout.ms` "
	"(alias `message.timeout.ms`) must be greater than "
	"`linger.ms` (alias `queue.buffering.max.ms`)";
	return "`message.timeout.ms` "
	"(alias `delivery.timeout.ms`) must be greater than "
	"`queue.buffering.max.ms` (alias `linger.ms`)";