Rewrite supported reference examples on the 2.x connector and projection APIs

[Tim55667757]

Goal

Replace 1.x-oriented reference examples with concise 2.x examples built on the canonical connector, query/projection, and output contracts.

Scope

• Rewrite supported examples instead of preserving unnecessary 1.x internal structure.
• Use provider-neutral connector interfaces and canonical domain projections.
• Use the standard output/rendering layer where examples need human-readable output.
• Keep provider-specific setup isolated and explicit.
• Retain only examples that demonstrate a clear supported 2.x workflow.
• Use legacy example defects as behavioral regression requirements rather than as reasons to preserve legacy implementation patterns.

Acceptance criteria

• Supported examples use canonical 2.x APIs rather than legacy internal state.
• Examples are small enough to serve as reference documentation.
• Invalid instruments and ordinary per-item failures have explicit behavior.
• Notification/output construction uses canonical adapters where applicable.
• Obsolete or redundant 1.x examples are retired instead of mechanically ported.