feat: add FetchUrlTool with proxy support and cross-OS path sanitization

- Implement native FetchUrlTool using reqwest for HTTP fetching, which respects HTTP_PROXY, HTTPS_PROXY, and NO_PROXY natively.
- Introduce sanitize_path in utils to bidirectionally handle Windows/WSL path mapping, applying it to various search/git handlers.
- Update .gitignore to exclude mcp_store.redb and tantivy_index.

server/src/handlers/git.rs

@@ -66,7 +66,8 @@ impl McpTool for GetActiveWorktreeContextHandler {
 
                     for delta in diff.deltas() {
                         if let Some(path) = delta.new_file().path() {
-                            files.push(path.to_string_lossy().into_owned());
+                            let path_str = path.to_string_lossy().into_owned();
+                            files.push(crate::handlers::utils::sanitize_path(&path_str));
                         }
                     }
                 }
@@ -121,7 +122,7 @@ impl McpTool for QueryGitDiffsHandler {
                     || change.git_commit.as_ref().is_some_and(|c| c.contains(&q))
                 {
                     matches.push(json!({
-                        "file_path": change.file_path,
+                        "file_path": crate::handlers::utils::sanitize_path(&change.file_path),
                         "description": change.description,
                         "commit": change.git_commit,
                         "branch": change.git_branch,