Track remaining low-risk cleanup from repository review

[apstndb]

Deferred from local repository review cleanup.

Context

The immediate repository hygiene and CLI safety/docs work is split into PRs, while larger architecture and jq streaming work is tracked separately. This issue keeps the remaining low-risk cleanup notes in one place so they are not lost.

Proposed cleanup items

• Remove the dead debuglog global/init block, or wire it into an actual debug path.
• Simplify enableTracing context cancellation if the extra context.WithCancel layer has no distinct cancellation semantics.
• Revisit the unreachable readWrite branch in lazy jq output routing and either remove it or make the invariant explicit near the eager override.
• Drop or use the currently unused mode parameter in jqresult.Compile.
• Review the no-op isEncodeLeaf(v) branch in jqresult.NormalizeForEncode.
• Consider rejecting NaN and +/-Inf parameters earlier with clearer messages instead of letting memebridge parsing surface a lower-level error.
• Add a minimal .golangci.yml only if the repo wants lint behavior pinned beyond the version already set in GitHub Actions.

Acceptance criteria

• Each cleanup is either implemented with focused tests or explicitly left out with a short rationale.
• Existing golden tests continue to pass.
• make lint and make test pass.

[apstndb]

Resolved by #77 and #76.

• Remove dead code and tighten parameter validation #77 removed the unused debug logging and redundant tracing cancellation layer, and added early rejection for non-finite parameter-file floats.
• Simplify jqresult internals while preserving the Compile API #76 removed the redundant jqresult normalization branch and unreachable read-write switch case. The Compile mode parameter remains intentionally for source compatibility even though compilation is mode-independent.
• A .golangci.yml is intentionally not added: the workflow pins the linter version and the current lint gate passes with zero issues. Revisit if repository-specific lint configuration becomes necessary.

Every cleanup item is now implemented or explicitly declined with rationale.