Pair output budgets with workflow success and recovery benchmarks

[devin-ai-integration]

Problem

PR #1174 added deterministic per-surface output budgets and actionability floors, including the
combined MCP text + structured payload. The remaining gap is a representative workflow-level
oracle: a smaller response can still cost more if it causes an extra observation, retry, or
re-orientation after an error.

Scope

Add a focused, recorded routine-workflow benchmark that pairs output cost with successful next-step
behavior:

• snapshot -i and unchanged-snapshot suppression;
• one mutation with --settle, including the unchanged-interactive tail;
• get text or get attrs;
• one actionable timeout/platform/selector failure that retains enough identity and session state
  for recovery;
• CLI and MCP projections where they differ.

Track stable fixture-level UTF-8 bytes plus command count, fallback observation count, retry count,
and whether recovery preserves the current session. Keep live device measurements informational.

Add or extend small-model SkillGym/help-conformance cases so the outcome oracle verifies the next
command without a redundant observation. Do not make model-in-the-loop execution a required PR gate
unless the existing infrastructure is already deterministic and credential-free; the recorded
contract remains the fast CI gate.

Constraints

• Do not optimize bytes by removing actionable refs, generation pins, stable error identity, retry
  guidance, or recovery handles.
• Do not gate on live simulator output sizes.
• Keep the work scoped to measurement and fixtures; response-default changes belong in a later,
  evidence-driven issue.

Acceptance criteria

• A deterministic routine workflow reports output bytes and follow-up/retry counts.
• Regression tests fail when the workflow requires a redundant observation or loses recovery
  fields.
• At least one small-model task covers the same next-step decision.
• pnpm test:output-economy, relevant benchmark tests, typecheck, lint, and Fallow pass.

Origin: post-#1174 architecture follow-up.

[devin-ai-integration]

Implementation session: https://app.devin.ai/sessions/11d4136fd70f4724b848f7e6ead026ec