docs: REPORT for TASK C1 (v0.99.0 shipped + live-validated) + CHANGELOG test-count fix

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PSK5g6qYLknKj8u3QAFEr6

CHANGELOG.md

@@ -31,7 +31,7 @@ class-C restore) deliberately NOT included — product-design work (C2).
   with an upgraded "may fail to start" WARN. Residual case documented: a restored volume tar
   carrying the OLD internal credential hash may still need a manual in-DB reset.
 
-Tests: +12 (api snapshots ×3, backup restore-points ×4, volume-dump gating ×3, secret-gen ×2 files);
+Tests: 272 → 286 top-level test funcs (+14: api snapshots ×3, backup restore-points ×4, volume-dump gating ×3, backup secret-gen ×3, stacks secret-gen ×1);
 all three fixes companion-red-proofed (hollow `[]` endpoint / removed volume gate / no-generation
 each fail their test). Full `go build && go vet && go test ./...` green.