Remove guest runtime prefix shim dependency

docs/PROGRESS.md

@@ -2541,3 +2541,81 @@ Next recommended step:
 1. focus directly on eliminating the remaining Guile / Shepherd compatibility-prefix shims from the guest runtime
 2. preserve `shepherd-pid1` as an experimental selectable boot mode while that cleanup proceeds
 3. once the runtime-prefix issue is reduced, reassess whether `shepherd-pid1` should replace the older `freebsd-init+rc.d-shepherd` path as the preferred Fruix boot architecture
+
+## 2026-04-02 — Post-Phase-10: removed runtime dependence on `/tmp` Guile / Shepherd compatibility-prefix shims
+
+Completed work:
+
+- removed the generated guest's runtime dependence on the old `/tmp` compatibility-prefix symlinks for Guile, guile-extra, and Shepherd
+- wrote the subphase report:
+  - `docs/reports/postphase10-runtime-prefix-shims-freebsd.md`
+- updated the prefix materializer in:
+  - `modules/fruix/system/freebsd.scm`
+  - bumped the prefix-materializer revision
+  - added deterministic post-copy sanitation for staged runtime prefixes
+- removed activation-time recreation of these guest-side shims from the generated activation path:
+  - `/tmp/guile-freebsd-validate-install`
+  - `/tmp/guile-gnutls-freebsd-validate-install`
+  - `/tmp/shepherd-freebsd-validate-install`
+- sanitized the staged guile-extra runtime so it no longer depends on those old prefixes for key module loading:
+  - patched `fibers/config.scm` to use `GUILE_EXTENSIONS_PATH`
+  - patched `gnutls.scm` to fall back to `GUILE_EXTENSIONS_PATH`
+  - removed stale compiled cache files that would otherwise retain the old prefix behavior:
+    - `fibers/config.go`
+    - `gnutls.go`
+- sanitized the staged Shepherd runtime so it no longer depends on the old temporary prefix for `shepherd config`:
+  - patched `share/guile/site/3.0/shepherd/config.scm`
+  - removed stale compiled cache file:
+    - `shepherd/config.go`
+- extended the real XCP-ng validation harnesses so they now explicitly check for:
+  - absence of the `/tmp` compatibility-prefix trees
+  - successful Guile module loading from the store-backed runtime
+- updated:
+  - `tests/system/run-phase9-xcpng-boot.sh`
+  - `tests/system/run-phase11-shepherd-pid1-xcpng.sh`
+
+Validation:
+
+- `tests/system/run-phase9-xcpng-boot.sh` passes on the real VM with:
+  - workdir: `/tmp/noshim-phase9-smoke-1775143001`
+  - `compat_prefix_shims=absent`
+  - `guile_module_smoke=ok`
+  - `ready_marker=ready`
+  - `shepherd_status=running`
+  - `sshd_status=running`
+- `tests/system/run-phase11-shepherd-pid1-xcpng.sh` passes on the real VM with:
+  - workdir: `/tmp/noshim-phase11-smoke-1775142712`
+  - `compat_prefix_shims=absent`
+  - `guile_module_smoke=ok`
+  - `ready_marker=ready`
+  - `shepherd_pid=1`
+  - `shepherd_status=running`
+  - `sshd_status=running`
+- a direct manual guest probe also confirmed that all three `/tmp` compatibility-prefix paths are absent while Guile can still load:
+  - `(fibers config)`
+  - `(gnutls)`
+  - `(shepherd config)`
+
+Important findings:
+
+- the remaining native-runtime problem was narrower than the earlier boot-manager issue:
+  - boot was already solved
+  - PID 1 was already solved
+  - the next real dependency to remove was the guest's reliance on temporary compatibility aliases
+- deleting the stale compiled cache files for the affected modules was important; otherwise Guile could continue using prefix-baked compiled forms even after the source modules were patched
+- this subphase removes runtime dependence on the old `/tmp` compatibility shims, but it does not yet guarantee that every embedded historical prefix string has disappeared from every binary or metadata artifact
+
+Current assessment:
+
+- Fruix now boots and runs from a store-backed Guile / Shepherd runtime arrangement on FreeBSD without needing guest-side `/tmp` compatibility-prefix symlinks
+- this now holds for both validated real-VM boot modes:
+  - `freebsd-init+rc.d-shepherd`
+  - `shepherd-pid1`
+- the main remaining cleanup is deeper and lower-level:
+  - move the local Guile / guile-extra / Shepherd build/install flow itself closer to a truly store-native prefix so the remaining baked strings disappear from the artifacts rather than merely becoming runtime-irrelevant
+
+Next recommended step:
+
+1. keep `shepherd-pid1` available as the stronger experimental boot architecture
+2. start pushing the local Guile / guile-extra / Shepherd build/install process itself toward a truly store-native prefix layout
+3. clean up the remaining historical prefix strings still present in binaries, libtool metadata, and pkg-config metadata where they still matter for developer/operator workflows