docs: migrate workflow to DooPlex-local execution

scripts/CHANGELOG.md

@@ -1,5 +1,21 @@
 # Felhom scripts — Changelog
 
+## install_skills.py — cross-platform (POSIX symlink / Windows junction) (2026-07-19)
+
+Claude Code now runs on DooPlex (Debian 13), where `mklink /J` does not exist — the script would
+have fallen through to COPY mode on every run, silently breaking the "repo edits are live
+immediately" property that makes `felhom.eu/skills/` the source of truth.
+
+- Link creation is now platform-dispatched behind `os.name == "nt"`: `os.symlink(..., 
+  target_is_directory=True)` on POSIX, the existing `mklink /J` on Windows. Copy-mode fallback,
+  idempotency, and the re-run warning are unchanged.
+- **`remove_existing()` had a real hazard on POSIX**: `os.rmdir()` fails on a symlink-to-directory,
+  which would have fallen through to `shutil.rmtree()` — and rmtree following a symlink into
+  `skills/` would have deleted the repo's own skill sources. It now unlinks symlinks explicitly
+  before any rmdir/rmtree path is reached. Existence checks use `os.path.lexists()` so a broken
+  link is seen and replaced rather than ignored.
+- Human-facing output says "symlink" or "junction" per platform.
+
 ## build-felhom-iso.sh v1.22.0 — the boot screen is ours, and it offers exactly one thing (R-38) (2026-07-19)
 
 **A boot menu is a product surface, and ours was Proxmox's.** Every ISO is now repacked after