Establish ConfigKit module and extraction baseline

docs/roadmap/implementation.md

@@ -2,7 +2,8 @@
 
 ## Status and ownership
 
-Status: ready for implementation; all stages are pending.
+Status: implementation in progress; Stage 1 is complete and later stages are
+pending.
 
 Audience: a `gpt-5.6-terra` coding agent implementing one stage per prompt, in
 ascending order. Each stage depends on every earlier stage being complete.
@@ -282,7 +283,25 @@ rendering must not reveal hidden value histories.
 
 ## Stage 1 — Establish the module and extraction baseline
 
-Status: pending.
+Status: complete.
+
+Completion evidence (2026-09-06):
+
+- Added module `gitea.maximumdirect.net/eric/ConfigKit` at Go 1.25.0 and the
+  documented root `configkit` package, with no loader API or runtime dependency.
+- Added the [source extraction inventory](../internal/extraction.md), recording the
+  clean Narratio revision `b68435128be1e24b94fc7ec259d6e9093669fd99` and
+  WeatherReporter revision `5d306a202471e10fe98923a1df27d0b0fce5c666`, assigned
+  symbols/cases, adaptations, and application-only behavior. No sibling checkout
+  is a build dependency and no fixture was needed at this boundary.
+- Updated the [development baseline](../development.md), [component
+  inventory](../internal/overview.md), and repository status. The parser remains
+  planned at `go.yaml.in/yaml/v4 v4.0.0-rc.6`; its module requirement remains
+  deferred until the real adapter in Stage 3.
+- Verified `go test ./...`, `go vet ./...`, `go build ./...`, `git diff --check`,
+  changed local links, and the introduced file set with Go 1.26.7 on linux/amd64.
+  No deviations were required. Paths, diagnostics, parsing, and all later behavior
+  remain assigned to subsequent stages.
 
 Read: feature [foundation](initial.md#existing-implementation-foundation),
 [consumer fit](initial.md#consumer-fit-and-intentional-migrations), all policies.