Shadow — compare bounded branches and retain their evidence #41

Planning representation replaced — 6 November 2026. The accepted Investigation and software-change applications outcome is retained in #62. Reopen one bounded task when selected. This closure does not mean the capability is complete or cancelled. The original scope and evidence below remain preserved; current selected work starts at #52.

Explore two alternatives against one pinned base and return a reviewed candidate or an honest non-decision.

Starting point: Current delivery: there is no branch store, execution strategy or cleanup implementation.

First working slice

• Persist a Simulation Intent and two independently generated branches with lineage, assumptions, unknowns and a shared bounded budget.
• Separate candidate generation from Hunter review and Drift evaluation; keep branch Context and any material workspaces isolated.
• Record a candidate Vision or explicit failure/ineligibility; cancel remaining work and retain a cleanup receipt, including unresolved residue.

Connections: Uses #29, #23 and #33; supports #39 and #40. Material execution requires #27/#28; an initial text-only trial must be labelled as such.

Later: Material branches, search strategies, pruning and historical replay. Promotion stays with the receiving owner; no branch must win.

References: ADR 31 · ADR 34.

Contribution entry: Implement two text-only branch records and rejection/cleanup fixtures.
Open decision: Choose the bounded branch strategy and independent evaluation contract.
Verification: No material execution required for the labelled first trial. Shared contribution and touched-docs rules: #52.