docs: split published site (docs/) from internal notes (notes/)

The docs/ tree previously conflated published-site content (3 pages
were in mkdocs.yml nav) with working notes (~18 files that just sat
in the repo). Restructure so each tree means one thing:

- docs/         everything here is built and shipped to docs.makerfloss.eu.
                Adds docs/presentations/ for the two Marp decks
                previously living under docs/møder/.
- notes/        repo-only working material, not built. Contains
                meetings/, todo/, dev/ (was docs/superpowers/), and
                communications/ (the launch Facebook post).
- sandbox/      test-mermaid.md, the Marp/Mermaid pipeline sandbox.

Other touches:
- Drop "_noter" suffix on meeting filenames; drop "_presentation"
  from the messaging deck's basename for symmetry with SoMe-taxonomi.
- Update CLAUDE.md and docs/index.md path references.
- Drop the now-redundant --exclude-dir=superpowers from
  build-slides.sh since superpowers/ is no longer under docs/.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

CLAUDE.md

@@ -8,7 +8,7 @@ This is a **documentation-only repository** for the MakerFLOSS initiative at Ora
 
 ## Working Norms
 
-From `docs/todo/2026-04-14_todo.md`:
+From `notes/todo/2026-04-14_todo.md`:
 
 - **Language**: English for code, docs, commits (meeting notes may be in Danish)
 - **Git**: Trunk-based development, feature branches, simple commit messages

build-slides.sh

@@ -15,7 +15,7 @@ find "$OUTPUT_DIR" -maxdepth 1 -name "*.html" -delete
 SLIDES=()
 while IFS= read -r f; do
   SLIDES+=("$f")
-done < <(grep -rl "^marp: true" "$REPO_ROOT/docs" --include="*.md" --exclude-dir=superpowers 2>/dev/null || true)
+done < <(grep -rl "^marp: true" "$REPO_ROOT/docs" --include="*.md" 2>/dev/null || true)
 
 if [ ${#SLIDES[@]} -eq 0 ]; then
   echo "No marp presentations found in docs/."

docs/index.md

@@ -18,5 +18,5 @@ jam-session community focused on self-hosted, open-source infrastructure.
 - **Environments:** containerised and reproducible.
 - **Hardware:** all setups documented (this site) and physically labelled.
 - **Decisions:** lightweight markdown decision logs under
-  [`docs/superpowers/`](https://forgejo.makerfloss.eu/sjat/MakerFLOSS/src/branch/main/docs/superpowers).
+  [`notes/dev/`](https://forgejo.makerfloss.eu/sjat/MakerFLOSS/src/branch/main/notes/dev).
 - **License:** FLOSS by default; MIT for what we build.