chore: land tree view-state, vault, Pi module split, and repo hygiene

Persist PageTree expand state via control-plane view-state and align
chevron/DOM with restored expansion; keep Sidex-style shallow page-tree
scan and drop the unused recursive scanner that only added cargo noise.

Add password vault workbench routes/runtime/skill/CLI, split page_ai_pi
into a module package, and retire Hermes/ACP/OpenHub recycle + root
harness evidence from the index while gitignoring recycle and local
diag dumps.

Archive superseded design/bugs docs under old/, point architecture at
ARCHITECTURE.md, and refresh smokes for Pi S1–S7, vault, and editor
regressions so the working tree can stay clean.

rust/crates/mnote-web/src/hermes_tools/manifest.rs

@@ -355,7 +355,7 @@ fn knowledge_rag_status_tool() -> Value {
     }
     json!({
         "name": "mnote.knowledge_rag.status",
-        "description": "查看当前知识库 provider 状态、dashboard 地址、source registry 和同步状态。默认 provider 是 RAGFlow；WeKnora/LightRAG 仅作为 legacy fallback。",
+        "description": "查看当前知识库 provider 状态、dashboard 地址、source registry 和同步状态。默认 provider 是 LightRAG；WeKnora/RAGFlow 仅作为 env 显式切换的备用 / 调试路径。",
         "schemaVersion": TOOL_SCHEMA_VERSION,
         "capabilityScope": ["knowledge_rag.read", "evidence.read"],
         "status": "available",
@@ -405,7 +405,7 @@ fn knowledge_rag_query_tool() -> Value {
     }
     json!({
         "name": "mnote.knowledge_rag.query",
-        "description": "向当前知识库 provider 提问，返回 provider 原始结果和经 MNote registry 映射、sourcePaths 后过滤的 references/citations。默认 provider 是 RAGFlow，WeKnora/LightRAG 仅 legacy fallback。用户要求链接、来源、引用或证据时优先调用；返回的 citationMarkdown 由 MNote 前端自动追加成可点击来源定位，agent 不应在最终回答中手写 /documents、mnote:// 或搜索引擎包装链接。",
+        "description": "向当前知识库 provider 提问，返回 provider 原始结果和经 MNote registry 映射、sourcePaths 后过滤的 references/citations。默认 provider 是 LightRAG；WeKnora/RAGFlow 仅 env 备用。用户要求链接、来源、引用或证据时优先调用；返回的 citationMarkdown 由 MNote 前端自动追加成可点击来源定位，agent 不应在最终回答中手写 /documents、mnote:// 或搜索引擎包装链接。",
         "schemaVersion": TOOL_SCHEMA_VERSION,
         "capabilityScope": ["knowledge_rag.read", "evidence.read"],
         "status": "available",