Move agent guides into agents/skills/

Leave agents/ ready for other agent artifacts like definitions and
prompts alongside the skills.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

agents/skills/install-scripts.md

@@ -0,0 +1,19 @@
+# Install Scripts
+
+Read this before working under `install/` or on the system/user setup commands.
+
+The ISO owns installation orchestration. This repo ships target-side setup
+commands and reusable setup leaves:
+
+- `bin/omarchy-setup-system` runs root-owned system setup during ISO finalization.
+- `bin/omarchy-setup-hardware` runs idempotent hardware-specific setup and is called by `omarchy-setup-system`.
+- `bin/omarchy-finalize-user` runs the per-user runtime finalization (skill symlinks, xdg-user-dirs, mime defaults, `install/user/all.sh`). Shipped user defaults are seeded by `/etc/skel` from `omarchy-settings`, not by this command. `bin/omarchy-reinstall-configs` is the explicit destructive resync of those defaults into an existing user's `$HOME`.
+- leaf scripts under `install/` are sourced by `run_logged $OMARCHY_INSTALL/path/to/script.sh` and intentionally do not have shebangs.
+- avoid `exit` in sourced setup scripts unless intentionally aborting setup.
+- use `$OMARCHY_INSTALL` and `$OMARCHY_PATH` instead of hard-coded Omarchy paths.
+- keep root-scoped hardware setup under `install/hardware/` and orchestrate it through `install/hardware/all.sh`.
+- keep every per-user setup leaf under `install/user/` (including `install/user/hardware/` and `install/user/first-run/`) so it is clear what must run for each user.
+- prefer helper commands for package and command checks where available.
+
+Raw `command -v`, `pacman`, and `pacman-key` are acceptable in package-helper
+contexts where direct package-manager behavior is the point of the script.