docs(agent): close #74 matrix + #75 V2 install (themed first boot)

Unattended env matrix flags shipped earlier; default arm V2: live ISO
rebuild + offline install + first-boot themed Boreal desktop.

agent/BACKLOG.md

@@ -28,15 +28,6 @@ in [`docs/ROADMAP.md`](../docs/ROADMAP.md); map in
 
 ## NEXT
 
-### 74. Unattended-install test matrix
-`test-install.sh` always LUKS+swap; add (or document) no-swap and
-explicit no-LUKS paths via env flags only. Cost: script + KVM time; V2.
-
-### 75. Installer template SoT — V2 install after ISO rebuild
-HM pre-activate now pulls starter packages (larger closure). Run
-`test-install.sh` (or equivalent) on a rebuilt live ISO and confirm
-first boot still themed. Cost: ISO + KVM; V2.
-
 ### 20. KVM runner → VM suite in CI `[human]`
 The remaining stretch of the CI item — checks-on-push is live and
 **green** (run #58; runner = gitea/act_runner docker, eval tier).

agent/JOURNAL.md

@@ -17,6 +17,18 @@ Template:
 
 ---
 
+## 2026-07-10 — #74 matrix flags + #75 V2 install (default arm)
+- **Task:** NEXT #74 unattended matrix · #75 SoT V2 install after ISO.
+- **Did:** `NOMARCHY_TEST_SWAP_GB` / `NOMARCHY_TEST_NO_LUKS` drive
+  `tools/test-install.sh` go.sh + first-boot LUKS skip; nixpkgs OVMF
+  fallback. Full offline install V2 (SWAP=2 LUKS) after live ISO rebuild
+  with starter packages — first-boot themed Boreal, no red banner.
+  Closed #74/#75. Other matrix arms scripted (not full-ISO re-run).
+- **Verified:** **V2** — install powered off ~460s; first-boot.png
+  viewed (`/tmp/nomarchy-vm-75/first-boot.png`): themed wallpaper +
+  waybar (logo, clock, modules), doctor glyph, no autogen banner.
+- **Next suggestion:** NEXT only #20 [human] + #41 [blocked:hw].
+
 ## 2026-07-10 — Loop batch land #64–#73 (parallel worktrees)
 - **Task:** agent-actionable NEXT #64–#73 via worktree agents; land on main.
 - **Did:** #64 MIGRATION snapshots · #65 real-uid chown · #66 theme-state