fix: use max() instead of min() in LinkResolver search fallback

The search fallback (strategy 5) was using min() to select the best match
from FTS results, which selected the WORST match instead of the best.
On both SQLite and Postgres backends, higher scores indicate better matches
(FTS rank, vector similarity normalized to [0,1], hybrid fusion). Using max()
correctly returns the highest-scoring result.

Fixes #640

Co-authored-by: Paul Hernandez <phernandez@users.noreply.github.com>
Signed-off-by: claude[bot] <41898282+claude[bot]@users.noreply.github.com>

src/basic_memory/services/link_resolver.py

@@ -302,7 +302,7 @@ class LinkResolver:
 
             if results:
                 # Look for best match
-                best_match = min(results, key=lambda x: x.score)  # pyright: ignore
+                best_match = max(results, key=lambda x: x.score)  # pyright: ignore
                 logger.trace(
                     f"Selected best match from {len(results)} results: {best_match.permalink}"
                 )