Record sequence resolution correspondence decision

docs/adr/0021-sequence-resolution-correspondence.md

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+# ADR 0021: Match Registered Records During Resolution Inspection
+
+## Status
+
+Accepted.
+
+## Date
+
+2026-11-02
+
+## Context
+
+Application resolution can change fields within sequences. Treating every
+sequence change as atomic prevents a field record from covering an individual
+edit. Registered collection identities also provide a way to relate a final
+record to its entry value when positions change, so inspection can retain the
+correct source evidence without confusing it with a prior index occupant.
+
+## Decision
+
+Compare equal-length ordinary lists recursively by position during resolution
+auditing. A length change requires coverage of the list or an ancestor. For a
+collection with an applicable application identity registration, match entry and
+final records only when both endpoints have valid, unique identities. A change
+in identity order or membership requires list or ancestor coverage, while
+surviving records retain their matched entry evidence. When matching is not
+available, audit a changed list as a whole without introducing an early identity
+failure. Final registration validation remains at its existing boundary.
+
+Match only the resolution-entry and final snapshots, within the same registered
+destination. Identity changes are removals and additions, not inferred renames.
+Records and helpers address final positions; entry queries remain fixed to entry
+coordinates, and helpers do not follow later moves automatically. A surviving
+record takes precedence at a reused position; collection inspection retains
+removed records' evidence, and absent historical positions remain inspectable.
+New records do not inherit a previous occupant's history or explicitness.
+
+Preserve recorded operations, source coordinates, sensitivity, and safe detached
+inspection. Resolution comparison is separate from public effective diff, which
+continues to present sequence changes atomically.
+
+This extends resolution inspection under [ADR 0003](0003-preserve-presence-and-resolution-history.md)
+while preserving the diff decision in [ADR 0010](0010-effective-configuration-diff.md),
+source combination and identity rules in [ADR 0017](0017-collection-sequence-policy.md),
+and lifecycle ordering in [ADR 0018](0018-cli-after-structural-resolution.md).
+
+## Alternatives Considered
+
+- **Keep all sequence changes atomic during resolution.** This forces whole-list
+  records for independent field edits and does not identify a moved record's
+  earlier evidence.
+- **Infer identities for every list.** Similar values or conventional field
+  names do not establish an application identity and could attach unrelated
+  history to a final record.
+- **Reconstruct every intermediate callback mutation.** This requires a new
+  mutation history and implies an ordering that endpoint snapshots cannot prove.
+
+## Consequences
+
+Resolution auditing and inspection must share entry-to-final correspondence,
+including explicit unmatched records, while preserving historical coordinates
+and conservative sensitivity masking. Source assembly and public path types do
+not change. The [implementation plan](../roadmap/implementation.md) tracks the
+work; the [configuration contract](../config.md) owns implemented behavior.