docs: project documentation — architecture, getting-started, packs, mcp, regtest

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docs/README.md

@@ -0,0 +1,25 @@
+# /etc/nixos/docs
+
+Index for the omni documentation.
+
+- **[`system-map.md`](system-map.md)** — *Start here if you're
+  returning to this stack or arriving fresh.* Cross-project map of
+  the aiolabs ecosystem: which repo does what, how the pieces fit
+  together, where keys live, deployment dependencies, and a
+  start-here runbook for common tasks.
+- **[`ARCHITECTURE.md`](ARCHITECTURE.md)** — omni-the-desktop:
+  Hyprland, themes, the mksystem layer, flake structure. Scope is
+  this dev box, not the broader stack.
+- **[`packs.md`](packs.md)** — the **core + opt-in packs** model:
+  `omni.packs.<name>.enable`, the pack catalog, enabling packs (on a
+  host, via presets/features, or standalone on another NixOS via
+  `nixosModules.<pack>`), the compat bridge, the bitcoin/nix-bitcoin
+  pack, and how to author + verify a new pack.
+- **[`deploy-strategy.md`](deploy-strategy.md)** — fleet caching,
+  GC policy, dry-run workflows, Nix-vs-OCI comparison. Relevant when
+  pushing changes to fleet hosts.
+- **[`mcp.md`](mcp.md)** — Claude Code MCP server configuration on
+  this machine.
+
+For the workspace-level conventions that cross-cut every repo in
+`~/dev/`, see `~/dev/CLAUDE.md`.