feat: prove Market through the Intelligence OS plane

[eamirian]

Outcome

Proves the existing competitive-price analyst journey through merged Core PR #141's same governed resource plane.

• assembles one exact PREPARED Case over the Shift/Signal supporting the reviewed Brief;
• reopens Observation, Entity, Shift, Signal, Case, Brief, Decision, Outcome, and Feedback identities;
• preserves the explicit no_action analyst disposition instead of fabricating an Action;
• keeps feedback non-live with no delivery authority or external effect;
• updates the Market roadmap and candidate evidence without changing released 0.6.0 compatibility metadata.

Verification

• full Market suite with World present: 135 passed, 1 optional/pre-existing skip
• focused 0.8 acceptance: 1 passed
• changed-file Ruff lint and format: passed

Public Core 0.4 truthfully skips the 0.8-only acceptance until Core 0.8 is released.