feat(theme): make Boreal the distro default

Seed theme-state.json and the downstream template from themes/boreal.json
(including border + empty settings). Point eval/schema fallbacks at Boreal
(theme.nix preset, plymouth and live-ISO splash colors, theme-shot, sync
error examples). Docs/TESTING and RECOVERY follow the new default.

Verified: state matches boreal palette; theme-contrast all pass.
preview.png for boreal still missing (picker plain-name; V3 capture).

agent/JOURNAL.md

@@ -17,6 +17,13 @@ Template:
 
 ---
 
+## 2026-07-09 — Default theme → Boreal (item #42)
+- **Task:** NEXT #42 — distro default theme Tokyo Night → Boreal (`VISION § B` / v1.0 bar).
+- **Did:** Seeded `theme-state.json` + `templates/downstream/theme-state.json` from `themes/boreal.json` (incl. border + settings). Eval fallbacks: `theme.nix` preset → boreal.json; plymouth + live ISO splash hex fallbacks; theme-shot / theme-sync examples; TESTING/RECOVERY wording.
+- **Verified:** V0 — state JSON matches boreal palette/fonts; `check-theme-contrast` 24×7 pass; py_compile theme-sync. Full `nix flake check --no-build` started but not waited (slow ISO eval). No V2 apply / V3 session.
+- **Pending:** `themes/boreal/preview.png` still missing (picker name-only) — left in PROPOSED theme polish; V2/V3 visual on hardware. Queue head now #43 Firmware.
+- **Next suggestion:** #43 System › Firmware or #44 doctor hardware.
+
 ## 2026-07-09 — Install contracts: swap=0 + unattended LUKS (workflow test run)
 - **Task:** VISION § v1.0 install golden path — PROPOSED install P0s (NEXT head blocked: item 14 wait-cron, 20 `[human]`, 33 V3 visual, 41 hw). Test of VISION→BACKLOG→verify→commit loop.
 - **Did:** (1) `nomarchy-install` passes `swapSize=0` when swap disabled (was always `"${SWAP_GB}G"` → `"0G"` still created `@swap`). (2) `disko-config.nix` treats `"0"` and `"0G"` as no-swap. (3) Unattended LUKS fail-closed: require `NOMARCHY_LUKS_PASSPHRASE` or `NOMARCHY_NO_LUKS=1`.