feat(rate): add PyQt Morris screening workflow

[d-sorgcodexagent]

Summary

• add an authority-backed Morris sibling workspace to the standalone PyQt6 Variation surface
• inject one app-lifetime private loopback authority through the shared launcher seam; no GUI physics fallback
• provide canonical base-centered factor bounds, validated design controls, capability gating, sequential threaded create/status/cancel, target-local ranked results, typed availability denominators, and accessible fail-closed states
• propagate exact valid Simulation bases while preserving the established derivation signal, fail closed for invalid/custom torque semantics, and generation-gate both Morris and legacy Variation against stale results
• retain running QThreads through nonblocking deferred close, pin request/job identity, invalidate edited-input evidence, and keep scientific result cells read-only
• update all four required Rate handoff/SPEC documents in the implementation commit

Verification

• full Rate suite: 913 passed
• focused workflow/integration/visualization: 74 passed
• independent exact-SHA review: GO; reviewer-focused 38 passed
• live private-authority smoke: 2 trajectories, 17 targets
• Ruff check/format, scoped MyPy (16 sources), diff check, 500-LOC and 1200-line budgets: passed

Stack and scope

• exact parent: 71c771fb73143f1839449d1cf5a1f5472a55f098 (draft PR feat(rate): add shared Morris UI contract #4399)
• exact head: 89eb7a0a3432158aa4ff6a3e188f874120337c28
• intentionally open: React integration child, Morris persistence/export, UpstreamDrift consumer replacement, and protected parent-first release

Tracks #4142 and #4144.