fix: resolve 75 mem-cli compilation errors

All errors were API mismatches — handler code calling wrong method
   names, wrong argument types, or missing imports/derives. No logic
   changes. Build now passes with SQLX_OFFLINE=true.

   Key fixes:
   - embed_text -> embed_one, Vector -> Vec<f32> conversion
   - extract_token: extract auth header from HttpRequest first
   - AuthError variants aligned to actual enum definition
   - recursive async fns boxed (dfs_paths in inference + path_finder)
   - missing derives (Default, Serialize), imports (sqlx::Row, Timelike)
   - borrow-after-move: compute .len() before struct field move
   - streaming_body -> streaming with Result<Bytes> for SSE
   - CI: add SQLX_OFFLINE=true for offline builds without DB

   25 files changed, 99 insertions(+), 81 deletions(-)

Co-authored-by: rock <[email protected]>

crates/mem-cli/src/handlers/synthesis.rs

@@ -517,11 +517,12 @@ pub async fn reasoning_paths_handler(
     let elapsed = start_time.elapsed().as_millis();
     info!("Paths: {} found in {}ms", paths.len(), elapsed);
 
+    let path_count = paths.len();
     crate::handlers::response_builder::success_response(ReasoningPathsResponse {
         source_id: body.source_id.clone(),
         target_id: body.target_id.clone(),
         paths,
-        path_count: paths.len(),
+        path_count,
         process_time_ms: elapsed,
     })
 }