docs+ops: rewrite CLAUDE.md, skills, runner for post-split topology

Post-monolith documentation and ops cleanup:

- CLAUDE.md rewritten end-to-end. Documents the 11 Portainer-managed stacks
  + raw-compose management plane, the single shared `edge` network, the
  SSD-vs-ZFS bind-mount tiering, the four deployment channels (git push
  for app stacks, runner for Caddyfile, apply-compose.ps1 for mgmt plane /
  Caddyfile / vault), and the fact that the repo is now canonical.
- homelab-apply skill rewritten for the new channels — no more `dc up -d`,
  no more monolith.
- homelab-ssh skill rewritten — no `dc` alias, plain `docker` against
  container names; per-stack compose ops via /data/compose/<id>/...
- homelab-sync skill + sync-prod.ps1 retired. The repo is canonical now;
  pulling from prod is the wrong direction.
- .github/workflows/deploy.yml: drop the dc up -d steps, gate on
  paths:[Caddyfile, .github/workflows/deploy.yml], reload caddy via
  `docker exec` (no longer through compose).
- apply-compose.ps1: drop -Compose and -DevStack flags; -Caddy now reloads
  via `docker exec caddy` (Caddy is in its own Portainer stack now).

No live container is touched by this commit. The runner workflow is
currently disabled at the repo level; re-enabling it makes Caddyfile pushes
auto-deploy again.

.github/workflows/deploy.yml

@@ -1,12 +1,21 @@
 name: Deploy to valhalla
 
+# Post-split deploy. The application stacks (foundry, media, notify, monitoring,
+# remote, owncloud, resume, famapp, authentik, dev) live under stacks/<domain>/
+# and are deployed by Portainer git polling — the runner does NOT touch them.
+# Caddy lives in its own Portainer git stack (stacks/proxy/) and is likewise
+# deployed by Portainer; this workflow only pushes the Caddyfile and triggers
+# a hot reload on the running Caddy container.
+
 on:
   push:
     branches: [main]
+    paths:
+      - Caddyfile
+      - .github/workflows/deploy.yml
 
 env:
   FORCE_JAVASCRIPT_ACTIONS_TO_NODE24: true
-  COMPOSE: docker compose -f /valhalla-lab/docker-compose.yml --env-file /valhalla-lab/.env
 
 jobs:
   deploy:
@@ -15,17 +24,7 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
 
-      - name: Push .env + compose
-        run: |
-          cp .env /valhalla-lab/.env
-          cp docker-compose.yml /valhalla-lab/docker-compose.yml
-
-      - name: Pull and apply compose
-        run: |
-          $COMPOSE pull
-          $COMPOSE up -d
-
-      - name: Reload Caddyfile
+      - name: Push Caddyfile and reload Caddy
         run: |
           cp Caddyfile /config/caddy/Caddyfile
-          $COMPOSE exec -T caddy caddy reload --config /etc/caddy/Caddyfile
+          docker exec caddy caddy reload --config /etc/caddy/Caddyfile