implemented 03-gitea-client.md: added Gitea API client for commit statuses, status mapping, and extensive tests

docs/plan/03-gitea-client.md

@@ -38,3 +38,16 @@ WireMock (already a test dependency, see `WireMockSmokeTest`):
 
 - `./gradlew ktlintFormat` then `./gradlew build` is green.
 - No call path throws when Gitea is unconfigured or down.
+
+## Execution Notes (2026-07-07)
+
+Implemented as designed; deviations and decisions:
+
+- Added `org.springframework:spring-web` as a dependency; `RestClient` lives there and `spring-boot-starter` alone does not provide it.
+- `publishStatus` takes a `BuildStatus` and maps it internally instead of a raw Gitea state string.
+  The forward mapping never produces `error` because the `BuildStatus` enum is exhaustive; legacy emitted `error` only for unknown status strings.
+- `readStatus` returns a sealed `GiteaStatusResult` (`Found`/`None`/`Disabled`/`Error`) so callers get explicit non-fatal error states instead of exceptions.
+- `resolveUsername` only requires `gitea.baseUrl` and `git.token`; legacy gated it on the full status-enabled check including owner/repo, which the `/api/v1/user` endpoint does not need.
+- Responses are read as strings and parsed with a dedicated Jackson `ObjectMapper` instead of RestClient message converters, keeping malformed-JSON handling explicit and independent of converter auto-detection.
+- The legacy "Build status deleted" description marker is not ported; it belongs to the result-delete feature of later steps.
+- No config changes were needed: `gitea.*` and `git.token` already exist in `GitTallyConfig`, the `init` templates, and `docs/configuration.md`.