Update post-depth idea-to-spec producer roadmap

[SoundBlaster]

Summary

• Refresh the producer-side backlog after structural-depth and depth-repair delivery.
• Link related issue/task (if any): cross-repo idea-to-spec roadmap sync.

Motivation

• The roadmap still carried stale next steps and an ambiguous custom-run promotion item.
• Producer ownership for fallback-free clarification and human-friendly aliases needed to be explicit without introducing a second depth metric.

Goals

• Plan browser-answerable clarification templates, candidate display aliases, and custom-run handoff reconciliation.
• Keep all tooling, schemas, artifacts, and runtime behavior unchanged.

Changes

• Add a near-term producer backlog to the graph versioning roadmap.
• Synchronize the corresponding DocC guidance and refine the cash-flow smoke follow-ups.

Spec Evidence

For SpecGraph logic/tooling changes, cite at least one existing SG-SPEC-####
or proposal ####. PR body is preferred; commit trailers with the same fields
are accepted. For a true no-impact change, use Spec-ID: NO-SPEC-IMPACT and
provide a rationale.

Spec-ID: NO-SPEC-IMPACT
Proposal-ID: N/A
Spec-Impact: docs-only
Spec-Rationale: This PR only updates roadmap and DocC planning text; it does not change SpecGraph behavior, schemas, lifecycle, tooling, or produced artifacts.

Validation

• Tests added/updated for changed behavior
• Local checks passed

Commands run:

git diff --check
make docc-sync

Results:

• git diff --check passed.
• make docc-sync passed.

Risks / Notes

• Backward compatibility impact: none; documentation only.
• Migration/config changes required: none.
• Known limitations: producer changes remain future focused slices.

Checklist

• PR title clearly describes the change
• Scope is focused and minimal
• Documentation updated (or N/A)
• Workflow/artifact changes distinguish presence from readiness/status
• Consumers prefer authoritative repaired/promoted/latest artifacts where relevant
• Temporary or intermediate paths are scoped to the current run/task where relevant
• No secrets or sensitive data added