dm-context-filter: live prompt still exposes Kimaki spawn guidance and noisy --user examples

[chubes4]

Problem

Data Machine-managed Kimaki sessions are still receiving generic Kimaki session-spawning guidance that dm-context-filter is supposed to strip or adapt. This is no longer just model self-report: the current live OpenCode session followed the surviving prompt guidance and spawned Homeboy fleet minion threads with --user 532385681268408341, causing Discord system messages that Franklin added chubes to every minion thread.

The behavior is wrong for background fleet/minion work. The controller thread should own user notification, while minion threads should run quietly unless user review is explicitly needed.

Evidence

Repository inspection shows:

• This site opencode.json loads /Users/chubes/.kimaki/kimaki-config/plugins/dm-context-filter.ts.
• The installed plugin strips several sections and strips --agent <current_agent> examples.
• The effective-prompt harness passes, but it only gates --agent leaks by default.
• Filtered snapshots still preserve --user in helper/minion spawning guidance.

Relevant files:

• bridges/kimaki/plugins/dm-context-filter.ts
• tests/effective-prompt/run.mjs
• tests/effective-prompt/snapshots/default.filtered.txt
• tests/effective-prompt/snapshots/no-agents-no-thread.filtered.txt

Current filtered snapshot still says, in the start-new-sessions section:

• kimaki send --channel ... --prompt your prompt here --user
• You can use this to spawn parallel helper sessions like teammates
• Prefer --user over --user name

That is exactly the guidance the live agent followed when spawning minions.

This is adjacent to #120, but narrower and actionable: even if the transform path were fully effective, the filtered prompt still keeps the wrong --user guidance for minion/fleet spawning.

Desired behavior

• Background helper/minion/fleet spawning examples omit --user by default.
• --user remains documented only for explicit user-facing notifications or cases where the user should be added to the new thread.
• The filtered prompt should make the distinction clear:
  • controller/minion fan-out: no --user
  • notification/user-review thread: use --user or an explicit mention
• Tests should fail if generic helper/minion spawn guidance contains --user.
• If dm-context-filter: strip operations don't reach model in live sessions despite tests passing #120 means transform output is still not reaching live model context, the implementation should either fix the live hook path or move this policy to a prompt surface that is proven to affect outgoing model context.

Acceptance criteria

• Update dm-context-filter or the owning Kimaki prompt integration so Data Machine-managed prompts do not recommend --user for generic helper/minion spawning.
• Add effective-prompt coverage that treats --user in the generic helper/minion spawn section as a leak.
• Preserve --user examples only in explicit user notification or user-add sections.
• Verify with the effective-prompt harness.
• If live enforcement still depends on dm-context-filter: strip operations don't reach model in live sessions despite tests passing #120, document the remaining live-path blocker in the PR and link it back to dm-context-filter: strip operations don't reach model in live sessions despite tests passing #120.

AI assistance

• AI assistance: Yes
• Tool(s): OpenCode (gpt-5.5)
• Used for: Issue drafted from live session behavior and repository inspection; Chris directed filing and dispatch.