fix: 7 项 E2E Bug 修复 — Dashboard 404 / 记忆去重 / 记忆注入 / invoice_id / Prompt 版本

P0:
- BUG-H1: Dashboard 路由 /api/v1/stats/dashboard → /api/v1/admin/dashboard

P1:
- BUG-H2: viking_add 预检查 content_hash 去重，返回 "deduped" 状态；SqliteStorage 启动时回填已有条目 content_hash
- BUG-M5: saas-relay-client 发送前调用 viking_inject_prompt 注入跨会话记忆

P2:
- BUG-M1: PaymentResult 添加 invoice_id 字段，query_payment_status 返回 invoice_id
- BUG-M2: UpdatePromptRequest 添加内容字段，更新时自动创建新版本并递增 current_version
- BUG-M3: viking_find scope 参数文档化（设计行为，调用方需传 agent scope）
- BUG-M4: Dashboard 路由缺失已修复，handler 层 require_admin 已正确返回 403

P3 (确认已修复/非代码问题):
- BUG-L1: pain_seed_categories 已统一，无 pain_seeds 残留
- BUG-L2: pipeline_create 参数格式正确，E2E 测试方法问题

desktop/src-tauri/src/viking_commands.rs

@@ -189,6 +189,36 @@ pub async fn viking_add(uri: String, content: String) -> Result<VikingAddResult,
     // Expected format: agent://{agent_id}/{type}/{category}
     let (agent_id, memory_type, category) = parse_uri(&uri)?;
 
+    // Pre-check for duplicates via content hash
+    use std::hash::{Hash, Hasher};
+    let normalized_content = content.trim().to_lowercase();
+    let content_hash = {
+        let mut hasher = std::collections::hash_map::DefaultHasher::new();
+        normalized_content.hash(&mut hasher);
+        format!("{:016x}", hasher.finish())
+    };
+
+    let agent_scope = uri.split('/').nth(2).unwrap_or("");
+    let scope_prefix = format!("agent://{agent_scope}/");
+
+    // Check for existing entry with the same content hash in the same agent scope
+    let pool = storage.pool();
+    let existing: Option<(String,)> = sqlx::query_as(
+        "SELECT uri FROM memories WHERE content_hash = ? AND uri LIKE ? LIMIT 1"
+    )
+    .bind(&content_hash)
+    .bind(format!("{}%", scope_prefix))
+    .fetch_optional(pool)
+    .await
+    .map_err(|e| format!("Dedup check failed: {}", e))?;
+
+    if existing.is_some() {
+        return Ok(VikingAddResult {
+            uri,
+            status: "deduped".to_string(),
+        });
+    }
+
     let entry = MemoryEntry::new(&agent_id, memory_type, &category, content);
 
     storage