feat(plugin): compaction-hygiene guidance — recommend safe compaction at seams

#834. The pre-compaction complement to the shipped post-compaction re-grounding
banner. Because Scribe records progress as you go (task status, work-logs,
decision notes), a compaction at a clean work-seam is lossless — so guide the
model to recommend it proactively rather than letting auto-compact fire mid-task.

Placed in the ALWAYS-loaded channels (operator wants it consistently in context,
not relevance-gated like a skill): MCP _INSTRUCTIONS (every handshake) + the
static SessionStart floor (every session, MCP-independent). Behavior: at the end
of a block of work in a long session, ensure in-flight state is logged, then tell
the operator it's a safe moment to /compact (naming what was logged); recommend
at seams, not every turn; the model can't run /compact itself.

plugin.json 0.1.8 → 0.1.9 so clients re-pull the static-context change.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

plugin/.claude-plugin/plugin.json

@@ -1,7 +1,7 @@
 {
   "name": "scribe",
   "description": "Scribe second brain 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), and your saved Scribe Processes auto-surfaced as skills (/scribe:sync). Replaces superpowers + file-memory with one app-backed plugin.",
-  "version": "0.1.8",
+  "version": "0.1.9",
   "author": { "name": "Bryan Van Deusen" },
   "mcpServers": {
     "scribe": {