feat(plugin): official Claude Code plugin with marketplace and seven workflow skills (#1088)

Ships an installable Claude Code plugin (/plugin marketplace add
erp-mafia/accounted) that bundles the MCP connection (OAuth, zero-key)
with seven short workflow skills following the Swedish bookkeeping
rhythm: start, bookkeep, check, month-close, vat, payroll, year-end.

Wrappers are deliberately thin: they ground in the agent briefing and
Accounted:// resources, load server-side workflow skills and regulatory
atoms via gnubok_load_skill at need, and stage every write for user
approval. No knowledge is duplicated into the plugin.

A vitest cross-checks every skill slug, atom id, resource URI, and tool
name the wrappers reference against the MCP server source, so a server
rename fails CI instead of a user's chat session.

Assessment and follow-ups in dev_docs/claude_plugin.md (local, dev_docs
is unpublished by design).

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

claude-plugin/.claude-plugin/plugin.json

@@ -0,0 +1,23 @@
+{
+  "name": "accounted",
+  "displayName": "Accounted",
+  "description": "Official Accounted plugin: Swedish double-entry bookkeeping flows for Claude. Connects your ledger over MCP and ships short workflow skills (daily bookkeeping, health check, month close, VAT, payroll, year-end) that work from the company's live data and load Swedish accounting knowledge from the product when needed. Every write is staged for your approval; nothing is booked on its own.",
+  "version": "0.1.0",
+  "author": {
+    "name": "Accounted (erp-mafia)"
+  },
+  "homepage": "https://app.gnubok.se/docs/api/connect-claude",
+  "repository": "https://github.com/erp-mafia/accounted",
+  "license": "MIT",
+  "keywords": [
+    "accounting",
+    "bookkeeping",
+    "sweden",
+    "sverige",
+    "bokforing",
+    "moms",
+    "bokslut",
+    "accounted",
+    "mcp"
+  ]
+}