Add HyDEbar prompt documentation and version bump

[RAprogramm]

Summary

• add docs/celi.md with the curated Codex task prompts for future HyDEbar development
• surface the new document in the README and bump the crate version to 0.1.1
• document the changes in CHANGELOG.md

Testing

• cargo +nightly fmt --
• cargo +1.90.0 clippy -- -D warnings (fails: existing dead_code and collapsible_if issues across the codebase)
• cargo +1.90.0 build --all-targets (fails: repository already contains mismatched lifetime syntax errors)
• cargo +1.90.0 test --all (not completed: interrupted after repeated build failures)
• cargo audit (completes with upstream "unmaintained" warnings in dependencies)
• cargo deny check (not run: cargo-deny installation via cargo install was interrupted due to long compile time)

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https://chatgpt.com/codex/tasks/task_e_68d49bb12410832b852f16d057b4d741