refactor: restructure project layout and add install.mjs

- Move src/ → plugin/ with subdirectories:
  - plugin/core/ (business logic, models, store, permissions, utils, memory)
  - plugin/tools/ (query, resources)
  - plugin/commands/ (placeholder for slash commands)
  - plugin/hooks/ (placeholder for lifecycle hooks)
  - plugin/index.ts (wiring layer only, no business logic)
- Add install.mjs with --install, --uninstall, --openclaw-profile-path
- Add skills/ and docs/ root directories
- Move planning docs (PLAN.md, FEAT.md, AGENT_TASKS.md) to docs/
- Remove old scripts/install.sh
- Update tsconfig rootDir: src → plugin
- Update README.md and README.zh.md with new layout
- Bump version to 0.2.0
- All tests pass

plugin/index.ts

@@ -0,0 +1,45 @@
+/**
+ * Yonexus Plugin Entry
+ *
+ * This file is the wiring layer: it initializes and re-exports the core
+ * Yonexus class along with models, tools, and memory adapters.
+ * No business logic lives here.
+ */
+
+// ── Core ────────────────────────────────────────────────────────────────
+export { Yonexus, type YonexusOptions } from "./core/yonexus";
+
+// ── Models ──────────────────────────────────────────────────────────────
+export { YonexusError } from "./core/models/errors";
+export type { ErrorCode } from "./core/models/errors";
+export type { AuditLogEntry } from "./core/models/audit";
+export type {
+  Action,
+  Actor,
+  Agent,
+  Department,
+  DocsScope,
+  DocsTopic,
+  Identity,
+  Organization,
+  QueryFilter,
+  QueryInput,
+  QueryOptions,
+  Role,
+  SchemaField,
+  Scope,
+  StoreState,
+  Supervisor,
+  Team,
+  YonexusSchema,
+} from "./core/models/types";
+
+// ── Tools ───────────────────────────────────────────────────────────────
+export { queryIdentities } from "./tools/query";
+export { ResourceLayout } from "./tools/resources";
+
+// ── Memory ──────────────────────────────────────────────────────────────
+export { ScopeMemory, type MemoryPort } from "./core/memory/scopeMemory";
+
+// ── Default export ──────────────────────────────────────────────────────
+export { Yonexus as default } from "./core/yonexus";