[ROSETTA] Repair modernization reduced-path prerequisites

[isolomatov-gd]

instructions/r3/core/workflows/modernization-flow.md routes small in-place upgrades to phases 2 and 6 only, while those phase definitions require phases 1 and 5 respectively. Define a coherent reduced-route contract with equivalent inputs or dependency closure, simulate the target-agent path, and regenerate all plugins.

[github-actions]

Rosetta Triage

Classification: bug, instructions — the small in-place modernization route has incompatible phase prerequisites.
Priority assessment: Medium. The defect blocks a documented supported route, but it does not affect the full migration route.

Findings:

• Confirmed: modernization-flow.md selects only Phases 2 and 6 for small in-place upgrades, but Phase 2 requires Phase 1 and Phase 6 requires Phase 5 plus cross-project-analysis.md.
• This conflicts with the workflow-wide sequential and no-skip contract. An agent must either violate a prerequisite or abandon the reduced route.
• The same source text is present in the generated instruction artifacts. Plugin regeneration is required after the canonical R3 repair.
• The current Phase 7/8 contracts still require reference and cross-project artifacts. The two-phase route cannot safely proceed to implementation without a separate bounded single-project final-review contract.

Suggestions:

• Define the reduced route as an explicit exception that takes precedence over the general phase sequence.
• Permit Phase 2 without Phase 1 only after recording that no reusable reference-library analysis is needed.
• Permit Phase 6 without Phases 4–5 only for a single-project in-place scope with no cross-project dependency; require the matching original spec and target constraints instead of cross-project-analysis.md.
• On a failed reduced-route condition, record the reason and resume the applicable full-path prerequisites. Do not weaken the full-route prerequisites globally.
• Record route selection, rationale, and skipped phases in the state file. Keep the full migration path unchanged.
• Add a focused route simulation/regression check for: one-project upgrade, dependency discovered during Phase 2, and full migration. Update the user-guide scenario with the final reduced-route contract.
• Make an explicit R2 backport decision; R2 has the same inconsistency but is KTLO.

Next steps: Repair the canonical R3 workflow and affected phase contracts, validate the three route simulations, then regenerate and verify all plugin outputs.

Automated triage by Rosetta agent