feat(knowledge): 可跳转 wikilink + 真实相关 note + 一对话多页

- [[wikilink]] 解析器：note id / vault_path / 标题 / vault 元页 / missing
- 前端 MarkdownRenderer 把非数字 [[...]] 渲染成可点链接，元页弹窗查看，缺失置灰
- vault 脚手架补建项目 hub 页，三个结构性链接（index/taxonomy/hub）始终可跳
- capture 时按标题+摘要+区分性标签检索同主题 note，注入真实 [[标题]] 到 Related + 记 related 图谱边
- LLM 提取支持 notes[] 数组，一次对话拆 1~4 页并按标题互链（multi_note_enabled 开关）
- 新增接口 POST /resolve、GET /notes/{id}/wikilinks、GET /vault-page
- 新增配置 related_notes_enabled / related_notes_limit / multi_note_enabled

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

offline-backend-20260512/backend/app/gateway/routers/knowledge.py

@@ -95,6 +95,10 @@ class SearchRequest(BaseModel):
     limit: int = Field(default=8, ge=1, le=50)
 
 
+class ResolveWikilinksRequest(BaseModel):
+    targets: list[str] = Field(default_factory=list, description="`[[wikilink]]` targets to resolve to note ids / vault pages.")
+
+
 # --------------------------------------------------------------------------- #
 # Helpers
 # --------------------------------------------------------------------------- #
@@ -198,7 +202,7 @@ async def ingest_thread(thread_id: str, body: IngestThreadRequest, request: Requ
         )
     except EmptyThreadError:
         raise HTTPException(status_code=400, detail="Thread has no sediment-able content")
-    return {"note": result["note"], "created": result["created"]}
+    return {"note": result["note"], "created": result["created"], "notes": result.get("notes", [result["note"]])}
 
 
 @router.post("/ingest/threads/batch")
@@ -356,6 +360,44 @@ async def search(body: SearchRequest, request: Request) -> dict[str, Any]:
     return {"items": items}
 
 
+# --------------------------------------------------------------------------- #
+# Wikilinks ([[...]] resolution + vault meta-page viewer)
+# --------------------------------------------------------------------------- #
+@router.post("/resolve")
+@require_auth
+async def resolve_wikilinks(body: ResolveWikilinksRequest, request: Request) -> dict[str, Any]:
+    """Resolve ``[[wikilink]]`` targets to navigable destinations.
+
+    Each target resolves to a knowledge note (``kind=note``), a vault meta/hub
+    page (``kind=vault``), or nothing (``kind=missing``). Powers clickable
+    wikilinks in the knowledge UI.
+    """
+    service = get_knowledge_service(request)
+    return {"resolved": await service.resolve_wikilinks(body.targets)}
+
+
+@router.get("/notes/{note_id}/wikilinks")
+@require_auth
+async def resolve_note_wikilinks(note_id: str, request: Request) -> dict[str, Any]:
+    """Resolve every ``[[wikilink]]`` found in a note's body in one call."""
+    service = get_knowledge_service(request)
+    resolved = await service.resolve_note_wikilinks(note_id)
+    if resolved is None:
+        raise HTTPException(status_code=404, detail="Knowledge note not found")
+    return {"resolved": resolved}
+
+
+@router.get("/vault-page")
+@require_auth
+async def get_vault_page(request: Request, path: str) -> dict[str, Any]:
+    """Return a raw vault Markdown meta/hub page (no DB note) by its path."""
+    service = get_knowledge_service(request)
+    page = service.read_vault_page(path)
+    if page is None:
+        raise HTTPException(status_code=404, detail="Vault page not found")
+    return page
+
+
 class MergeRequest(BaseModel):
     primary_id: str
     duplicate_ids: list[str] = Field(default_factory=list)