Validate FreeBSD Fruix rootfs trees

docs/PROGRESS.md

@@ -1960,6 +1960,87 @@ Current assessment:
 - Phase 7.2 is now satisfied on the current FreeBSD prototype track
 - the next step is to materialize and statically validate an installable root filesystem tree from this system closure
 
+## 2026-04-01 — Phase 7.3 completed: installable rootfs tree validated from the system closure
+
+Completed work:
+
+- added the Phase 7.3 rootfs materialization harnesses:
+  - `tests/system/materialize-phase7-rootfs.scm`
+  - `tests/system/run-phase7-rootfs.sh`
+- wrote the Phase 7.3 report:
+  - `docs/reports/phase7-rootfs-freebsd.md`
+- ran the rootfs harness successfully and captured metadata under:
+  - `/tmp/phase7-rootfs-metadata.txt`
+
+Important findings:
+
+- the declarative Fruix FreeBSD system can now be materialized as a root filesystem tree rather than only as a store closure directory
+- the rootfs uses a Guix-like anchor:
+  - `/run/current-system`
+  so that boot assets, generated configuration, and system-profile content remain tied to the declarative system closure
+- static validation confirmed:
+  - boot asset linkage
+  - generated `/etc` linkage
+  - activation payload presence
+  - Shepherd `rc.d` launch integration
+  - declared filesystem entries
+  - declared user/group provisioning in the activation path
+  - deterministic ready-state wiring through `/var/lib/fruix/ready`
+- observed metadata confirmed:
+  - `rootfs=/tmp/.../rootfs`
+  - `closure_path=/frx/store/...-fruix-system-fruix-freebsd`
+  - `run_current_system_target=/frx/store/...-fruix-system-fruix-freebsd`
+  - `activate_target=/run/current-system/activate`
+  - `bin_target=/run/current-system/profile/bin`
+  - `sbin_target=/run/current-system/profile/sbin`
+  - `boot_kernel_target=/run/current-system/boot/kernel`
+  - `boot_loader_target=/run/current-system/boot/loader`
+  - `boot_loader_efi_target=/run/current-system/boot/loader.efi`
+  - `rc_conf_target=/run/current-system/etc/rc.conf`
+  - `rc_script_target=/run/current-system/usr/local/etc/rc.d/fruix-shepherd`
+  - `ready_marker=/var/lib/fruix/ready`
+  - `validation_mode=static-rootfs-check`
+
+Current assessment:
+
+- Phase 7.3 is now satisfied on the current FreeBSD prototype track
+- Phase 7 as a whole is now complete on the active FreeBSD amd64 prototype path
+
+## 2026-04-01 — Phase 7 completed on the current FreeBSD prototype track
+
+Phase 7 is now considered complete for the active FreeBSD amd64 prototype path.
+
+Why this milestone is satisfied:
+
+- **Phase 7.1** success criteria were met on the prototype track:
+  - a minimal Fruix operating-system object now exists for FreeBSD
+  - it evaluates into a coherent system-closure specification
+- **Phase 7.2** success criteria were met on the prototype track:
+  - that system model now materializes into a reproducible closure under `/frx/store`
+  - the closure contains boot assets, generated `/etc` files, activation payloads, and Shepherd launch integration
+- **Phase 7.3** success criteria were met on the prototype track:
+  - the closure now materializes into a concrete rootfs tree
+  - the resulting rootfs passes static validation for later image-construction work
+
+Important scope note:
+
+- this completes the **declarative system-composition milestone** for the current prototype track, not a fully booted Fruix guest yet
+- the current output is a validated closure plus rootfs tree; Phase 8 still needs to turn that into a reproducible bhyve-friendly disk image
+- the chosen first system-init strategy remains:
+  - FreeBSD init + `rc.d` launching Shepherd
+  rather than Shepherd-as-PID-1
+- the current system model remains Fruix-owned and FreeBSD-oriented rather than attempting full upstream Guix System integration prematurely
+
+Next recommended step:
+
+1. begin Phase 8.1 by creating a reproducible disk-image build path from the generated Fruix rootfs tree
+2. keep the current init decision explicit for the first boot target:
+  - FreeBSD init + `rc.d` + Shepherd
+3. continue preserving the selective Fruix naming policy:
+  - Fruix at the product boundary
+  - `/frx` as the canonical store root
+  - stable upstream-derived internal names unless there is strong architectural value in renaming them
+
 Current assessment:
 
 - Phase 7.1 is now satisfied on the current FreeBSD prototype track