[DISCUSS] Turning the simplification audit into issues

[Astro-Han]

PR #3545 removed more than 13,000 lines by collapsing several compaction paths into one authority. We used the same test on the rest of the repository: if a type, state, bridge, or facade disappeared, what real behavior would we lose?

The audit found five larger candidates that look ready for implementation:

• fold RuntimeRunner and the Invocation/Flow shell into RuntimeKernel;
• remove the old Session/AgentRun inspection documents while keeping Session and Turn traces;
• ship one Eval runtime in the npm CLI package instead of two copies;
• reduce the Windows sandbox launcher to the selected --broker-local path;
• narrow maka-cu to the macOS host executor that Maka actually uses.

It also found smaller cases such as write-only projection tables, producerless states, duplicate DTO fields, and private extension points with no consumer. Some remove only a few lines, but they still remove a maintenance contract. Product questions and candidates with unresolved migration or compatibility work are not in this draft.

I do not want to open thirty issues without giving the community a chance to challenge the audit first. The attached draft contains the proposed issue boundaries and the evidence we used.

Full working draft

The proposed rule for each issue is simple: one end-to-end deletion, one PR, and a strict reduction in maintained concepts. Moving the same idea behind a new facade or compatibility bridge does not count.

Please point out any current consumer, compatibility obligation, overlapping work, or behavior that the draft missed. Unless the discussion changes the direction, we will revise the list and open the remaining issues unassigned after 2026-08-26 13:39 UTC.

Codex agents helped trace consumers and prepare the working draft. A human contributor still needs to verify each issue and own any resulting change.