feat(rag): harden post-LightRAG runtime

Retire legacy OCR/media/evidence fallbacks, add local-folder event bus and Page Aggregate guards, and archive completed design checklists.

Validation: cargo test -p mnote-web -- --test-threads=1; cargo test --workspace -- --test-threads=1; git diff --check; codegraph sync .; codegraph_status.

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

@@ -290,6 +290,7 @@ fn doc_find_tool() -> Value {
     })
 }
 
+// 旧 evidence 工具仅保留为历史对照；当前 manifest() 不注册这些工具，资料库问答走 mnote.knowledge_rag.*。
 #[allow(dead_code)]
 fn evidence_search_tool() -> Value {
     let mut properties = base_identity_properties();
@@ -434,13 +435,13 @@ fn knowledge_rag_query_tool() -> Value {
             json!({
                 "type": "array",
                 "items": { "type": "string" },
-                "description": "可选 MNote workspace 相对路径范围；可传文件或目录，返回 references 会限制在这些来源内。"
+                "description": "可选 MNote workspace 相对路径范围；可传文件或目录。当前语义是 LightRAG provider 检索后，MNote 只过滤返回的 references；provider raw 仍可能是全局结果。"
             }),
         );
     }
     json!({
         "name": "mnote.knowledge_rag.query",
-        "description": "向 LightRAG 资料库提问，返回 provider 原始结果和经 MNote registry 映射后的引用。",
+        "description": "向 LightRAG 资料库提问，返回 provider 原始结果和经 MNote registry 映射、sourcePaths 后过滤的引用。",
         "schemaVersion": TOOL_SCHEMA_VERSION,
         "capabilityScope": ["knowledge_rag.read", "evidence.read"],
         "status": "available",
@@ -477,6 +478,7 @@ fn knowledge_rag_open_reference_tool() -> Value {
     })
 }
 
+// 旧 local index agent 工具仅保留为历史对照；当前 manifest() 不注册这些工具。
 #[allow(dead_code)]
 fn index_status_tool() -> Value {
     let mut properties = base_identity_properties();