fix: transport escalation exempts log reads, get_entity accepts slug alias, add restart_service + push_file tools

P0: Transport escalation in classifyAndGate (server.go:745) now exempts
    log-inspection commands (tail/head/cat/journalctl on *.log or /logs/)
    from the /opt//etc//var/lib/ gating on LXC targets. Fixes the
    'tail -3 /opt/seanime/data/logs/seanime.log queued for approval' bug.

P1: queryEntity returns actionable error when slug_or_id param is empty
    ('slug_or_id is required') instead of silent 'entity not found: '.

P2: Added slugArg() helper (server.go) so get_entity, get_relations,
    get_blast_radius, and explain accept 'slug' as an alias for their
    declared param name. Solves the discoverability inconsistency where
    every tool used a different param name for the same concept.

P3: Two new MCP tools:
    - restart_service(target, service) — systemctl restart wrapper,
      correctly classified config_mutation (requires approval)
    - push_file(target, source_path, dest_path, backup=true) — pct push
      from Proxmox host into LXC, with optional backup. Classified
      config_mutation. LXC-only for now.

P4: Updated homelab-lxc-ops skill with MCP tools preference table.

Plus: Wails desktop build now uses build-tag approach for frontend embed
      (assets_embed.go + assets_stub.go), so go build ./... works on
      clean checkout without the frontend built first.

Version: 0.31.0 → 0.32.0

cmd/desktop/assets_stub.go

@@ -0,0 +1,12 @@
+//go:build !desktop
+
+package main
+
+import "embed"
+
+// assets is an empty FS for the default (non-desktop) build. The real embedded
+// SPA lives in assets_embed.go behind the `desktop` build tag, because
+// frontend/dist is a gitignored artifact that only exists after `make desktop`
+// copies web/dist/* into it. This stub lets `go build ./...` compile cleanly on
+// a fresh checkout without the frontend built.
+var assets embed.FS