feat: scaffold go backend foundation

.planning/STATE.md

@@ -7,7 +7,7 @@ See: `.planning/PROJECT.md` (updated 2026-04-26)
 **Core value:** The user should feel and prove that they are becoming more
 interview-ready after each short practice loop.
 
-**Current focus:** Phase 1: Go Backend Foundation and Workflow Boundary.
+**Current focus:** Phase 2 planning: Diagnostic Interview Loop.
 
 ## Current Decisions
 
@@ -21,13 +21,15 @@ interview-ready after each short practice loop.
 - OpenSpec is the intent/requirements source of truth.
 - First interview track is Backend Developer Interview.
 - Phase 1 has context, research, and plan artifacts.
+- Phase 1 Go backend scaffold is implemented and verified.
 
 ## Next Actions
 
-1. Execute Phase 1 Go backend foundation plan.
+1. Plan Phase 2 diagnostic interview loop with GSD.
 2. Keep `docs/planning/WORKFLOW_CONTRACTS.md` aligned with Go structs during
-   implementation.
-3. After Phase 1, plan Phase 2 diagnostic interview loop.
+   future workflow implementation.
+3. Decide whether Phase 2 starts with in-memory diagnostic sessions or a small
+   persistence boundary.
 
 ## Validation Log
 
@@ -35,6 +37,9 @@ interview-ready after each short practice loop.
   before GSD planning docs were created.
 - 2026-04-26: First track, workflow contracts, and Phase 1 GSD plan were
   created.
+- 2026-04-26: Phase 1 implementation verified with `go test ./...`,
+  `openspec validate bootstrap-job-tutor-platform --strict`, and Go source
+  line-count check.
 
 ---
 *State initialized: 2026-04-26.*