fix: nomarchy-manual opens local README, not an Omarchy URL

The script hardcoded `xdg-open https://learn.omacom.io/2/the-nomarchy-manual`
— an upstream Omarchy page. Users hitting "Help → Manual" in nomarchy-menu
were sent to an unrelated site, and there's no nomarchy.org canonical
docs URL to point at instead.

Now opens `$HOME/.local/share/nomarchy/README.md`, which lives on every
installed system (per SKILL.md's "Out of Scope" note about
`~/.local/share/nomarchy/`) and links every doc in `docs/`. Falls back
to a notify-send "run nomarchy-update?" message if the source tree
isn't synced.

Pillar 6 entry in docs/ROADMAP.md updated to (Shipped).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

features/scripts/utils/nomarchy-manual

@@ -1,10 +1,18 @@
 #!/usr/bin/env bash
 set -e
 
-# Nomarchy Manual Script
-# Opens the Nomarchy manual in the default web browser.
+# Open the Nomarchy docs index in the default handler.
+# On an installed system the source tree lives at ~/.local/share/nomarchy/
+# (see SKILL.md's "Out of Scope" section), so the README — which links every
+# doc in docs/ — is the canonical "open the manual" target.
 
-URL="https://learn.omacom.io/2/the-nomarchy-manual"
+README="$HOME/.local/share/nomarchy/README.md"
 
-echo "Opening Nomarchy manual: $URL"
-xdg-open "$URL"
+if [[ -f "$README" ]]; then
+  echo "Opening Nomarchy manual: $README"
+  xdg-open "$README"
+else
+  notify-send "Nomarchy Manual" \
+    "Source tree not found at $README. Try \`nomarchy-update\` to sync it."
+  exit 1
+fi