Add retrieval CLI surface

[TheGreenCedar]

Summary

• Adds retrieval CLI bootstrap/status/search surfaces and Cargo aliases.
• Updates JSON output, stdio/http transports, and CLI contract tests for fail-closed sidecar-primary retrieval.
• Adds the retrieval generalization lint guard once the CLI literals are removed.

Tests

• cargo check -p codestory-cli
• cargo test -p codestory-cli --test retrieval_bootstrap_contracts
• cargo test -p codestory-cli --test search_json_output
• cargo test -p codestory-cli --test stdio_protocol_contracts
• cargo test -p codestory-cli --test http_transport_contracts
• cargo test -p codestory-runtime --test retrieval_generalization_guard
• cargo fmt --check
• git diff --check

Stack

Base: codex/accuracy-pass-03-runtime-retrieval (#13)
Next: codex/accuracy-pass-05-benchmark-eval