Add premium performance budget guardrail

[r3dbars]

Summary

• add pass/fail thresholds to the Home recent-captures benchmark
• wire the deterministic benchmark into scripts/ops/performance-budget.rb
• add a Swift CI premium performance budget step after the app build

CI vs manual proof boundary

• CI now checks deterministic Home list loader latency and cancellation acknowledgement.
• CI does not claim meeting-list 120fps hardware proof; that still needs Apple Silicon manual/hardware verification.
• Launch-to-interactive runtime proof remains existing launch smoke/runtime telemetry territory, not newly faked here.

Checks run

• ruby -c scripts/ops/performance-budget.rb
• bash -n scripts/dev/benchmark-home-recent-captures.sh
• scripts/dev/benchmark-home-recent-captures.sh --max-average-load-ms 500 --max-cancellation-ms 100
• scripts/ops/performance-budget.rb --app /Users/redbars/.codex/worktrees/dfed/transcripted-latest/build/Transcripted.app --check-home-recent-captures --allow-missing-parakeet-model --max-app-mb 220 --max-resources-mb 80
• python3 scripts/dev/check-build-source-lists.py
• scripts/dev/agent-preflight.sh

Not run locally

• bash build.sh --no-open
• bash run-tests.sh

lanes used: Codex=implemented, tested, committed, pushed, opened PR; Claude=skipped; Local=first-pass scan proof at /Users/redbars/.codex/maestro/runs/20260703T001605Z-transcripted-ws42-perf-scan-local; Windows=skipped