Integrate offline encoder artifact boundary and Shadow Lab contracts after EEG branch convergence

[aurascoper]

Tracks the planning-and-contract package archived from #30, which was closed
without merging to avoid deepening an already-forked staging topology. The PR
itself declared base_is_authoritative: false, so keeping it open made the
review queue look actionable when the change explicitly was not.

Archived state

archived PR:  #30
branch:       docs/eeg-offline-encoder-boundary  (retained, do not delete)
branch head:  1251b5b
original base: research/eeg-fusion-base

Commits

e66bd09  research(eeg): register offline encoder artifact boundary
c814235  docs(eeg): define the EEG Shadow Lab MVP scope
1251b5b  research(eeg): graduated execution states and fail-closed fusion v1

The PR body named only the first two. 1251b5b is not incidental — it is the
branch head and contributes independently:

NeuralComposeEEG/schemas/nc-eeg-fused-state-v1.schema.json   (new)
docs/science/predictive-processing-background.md             (new)
docs/architecture/eeg-shadow-lab-mvp.md                      (extended)
NeuralComposeEEG/tests/test_shadow_scope_contract.py         (extended)
docs/architecture/decision-log/ADR-011-...                   (extended)

Any future integration must account for all three commits, not the two named in
the original description.

Disposition

target:            undecided until EEG branch convergence
runtime authority: none
promotion status:  not eligible

Integration will occur by rebase after the currently divergent EEG branches
converge, or by selective cherry-pick of the three commits above. No application
runtime, model execution, live control, or promotion authority is granted by
this package in the meantime.

Reopening condition

Revisit once research/eeg-fusion-base and docs/eeg-methods-scope converge, at
which point the artifact boundary (ADR-011) and Shadow Lab MVP scope can be
retargeted onto a single authoritative base.