refactor(systems): one seam — the Systems question rides every read and write of a record

Scribe issue #2570, from the operator's challenge: the invariant is
"always be asking whether what you're touching is a System's territory
and whether the work is filed there" — not a nudge in one corner. The
prior shape failed it twice: the hint fired only on creates (with a
special-cased zero-Systems branch), and get_task/get_note returned
records WITHOUT their Systems, so the read-side reflex had nothing to
fire on (same per-kind asymmetry as #2481).

- attach_systems(): single helper used by get/create/update for tasks,
  notes, and snippets, plus add_task_log. Tagged records always show
  `systems`; an untagged project record carries the `systems_hint`
  question instead. Neither field attaches empty (#2483). Hint is
  owner-only; everything fail-open (#2109).
- untagged_systems_hint unified to ONE question — the vocabulary
  listing varies, the question doesn't; the zero-Systems branch stops
  being special text.
- Docstrings state the uniform contract; floor prose now names the
  read-side reflex (systems visible -> list_system_records the pile).
- Plugin 0.1.27 -> 0.1.28.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

plugin/.claude-plugin/plugin.json

@@ -1,7 +1,7 @@
 {
   "name": "scribe",
   "description": "Scribe system-of-record for Claude Code: MCP tools over your notes/tasks/projects/rules, a session-start push channel that surfaces your always-on rules + active-project context, process-skills (writing-plans, systematic-debugging, verification, brainstorming, reusing-code), and your saved Scribe Processes auto-surfaced as skills (/scribe:sync). Replaces superpowers + file-memory with one app-backed plugin.",
-  "version": "0.1.27",
+  "version": "0.1.28",
   "author": { "name": "Bryan Van Deusen" },
   "mcpServers": {
     "scribe": {