Add #[provide] telemetry attribute to derived errors

[RAprogramm]

Summary

• teach the derive macro to accept #[provide(ref = ..., value = ...)] field attributes and emit the matching provide code for structs and enums
• surface the new telemetry hooks in the README and bump crate versions to 0.8.0 / 0.4.0 with changelog updates
• extend the integration suite with runtime regressions that request references and values via std::error::Request

Testing

• cargo +nightly fmt --
• cargo clippy -- -D warnings
• cargo build --all-targets
• cargo test --all
• cargo doc --no-deps
• cargo deny check
• cargo audit

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https://chatgpt.com/codex/tasks/task_e_68ce2db60798832bb5ff43a723718556