Plan main-relative companion inputs

docs/roadmap/main-relative-inputs.md

@@ -1,7 +1,7 @@
 # Main-relative companion imports and overlays
 
-Status: all four design decisions settled; not implemented. Final API spelling
-and implementation planning remain. Baseline: `191015e`.
+Status: design settled; not implemented. The [implementation plan](implementation.md)
+owns the concrete API spelling, execution order, and verification. Baseline: `191015e`.
 
 ## Purpose
 
@@ -205,74 +205,6 @@ architectural exclusions. The design follows
 follow-up for deferred context ownership without rewriting accepted decisions.
 No release version or additional release gate is selected here.
 
-## Work from the baseline
-
-1. **Finalize API spelling and examples.** Translate the settled decisions below
-   into concrete declarations and prepare Go examples for Audita's mapping/bytes
-   workflow, explicit overrides, non-file main contexts, and independently located
-   embedded inputs.
-2. **Carry binding intent through the public facade and load request.** Update
-   the relevant input/options declarations and conversions in `layered.go` and
-   `lifecycle.go`, retaining root-owned public types and normal ownership rules.
-   Distinguish a deferred relationship from a concrete filesystem context.
-3. **Bind underlay import contexts after main context resolution.** Extend
-   preparation and acquisition in `internal/engine/load_request.go`, `load_input.go`, and
-   `acquisition.go` as needed. Reuse the main's resolved base, root, and namespace,
-   apply the settled missing-base policy, and delegate selection to existing import
-   machinery. Preserve independently supplied contexts.
-4. **Derive overlay context and separate lookup from containment.** Remove the
-   unconditional explicit-context requirement for the new layered default.
-   Preserve explicit and ordinary lookup while using the main context's resolved
-   base inside a potentially wider root. Reuse selected-overlay loading and its
-   failure and resource-ownership behavior.
-5. **Verify the complete workflow and document it.** Add maintained consumer
-   examples, public integration coverage, and focused engine tests. Update the
-   discovery, layered-loading, import-context, and selected-overlay contracts,
-   declaration comments, and internal ownership documentation when implemented.
-
-This is dependency order for a later implementation plan, not a required commit
-layout or a requirement to expose intermediate stages to consumers.
-
-## Validation and completion
-
-Validate behavior through the public loading boundary, including:
-
-- Explicit and discovered main files, early and later search candidates, and an
-  unrelated invocation directory. Companions follow the same selected main.
-- Native file mains, bytes/readers/mappings with explicit host or native contexts,
-  and absent mains with explicit contexts. Cover absent host root-only contexts,
-  missing and invalid contexts, and context reuse without enabling main imports.
-- Mapping, bytes, and reader underlays containing optional named-file and recursive
-  directory imports with `*.yml`/`*.yaml` filtering and mounted destinations.
-- Receiving-input scope: active bindings on main inputs and file-backed underlays
-  fail with option errors; concrete context overrides retain their precedence.
-- File only, directory only, both, neither, empty directories, and invalid or
-  unreadable selected fragments. Both forms compose as peers when present.
-- Operator prompt overrides above embedded catalogs using registered identity;
-  same-tier duplicate IDs remain conflicts. Main and overlay precedence survive.
-- Mixed embedded and companion inputs, multiple underlay tiers, transitive
-  imports, placement, source-version checks, and load-wide import defaults.
-- Automatic derived overlays and explicit overrides, active and inactive names,
-  broader containment roots, and missing selected overlays.
-- Optional discovery exhaustion, required discovery, fallback and skip policies,
-  mixed payload/required-import cases from OD-2, and terminal selected-main errors.
-- Unused fallback paths need not exist or be accessible; selected fallback paths
-  receive normal validation. Inactive overlays ignore fallback settings.
-- Empty `path: []` with either requiredness value when no base exists, including
-  the independent effect of `RequireBase`, and skipped imports without fabricated
-  completed-search evidence.
-- Symlinks, eligible namespaces, parent-relative paths within the selected scope,
-  context validity, and namespace identity under OD-3 and OD-4.
-- Normal source evidence, diagnostics, passive resource contexts, cleanup, and
-  budget accounting; no duplicate lifecycle callbacks or preliminary full load.
-- Existing ordinary and explicit layered workflows and description reuse.
-
-Run focused checks during implementation and applicable normal repository checks
-before completion. No benchmark campaign is required. Completion means the
-application can discover its main, bind companion imports and the selected
-overlay, and receive normal resolved configuration and inspection in one load,
-without an application directory walker, parser, or extra discovery pass.
-
 ## Settled Decisions
 
 ### OD-1: Public representation of deferred context binding — settled