fix: set hasResolvedPath flag after ensuring column exists

detectSchema() runs at DB open time before ensureResolvedPathColumn()
adds the column during Load(). On first run (or any run where the column
was just added), hasResolvedPath stayed false, causing Load() to skip
reading resolved_path from SQLite. This forced a full backfill of all
observations on every restart, burning CPU for minutes on large DBs.

Fix: set hasResolvedPath = true after ensureResolvedPathColumn succeeds.

cmd/server/main.go

@@ -157,6 +157,8 @@ func main() {
 	// AND to SQLite. On next restart, detectSchema finds the column and Load() reads it.
 	if err := ensureResolvedPathColumn(dbPath); err != nil {
 		log.Printf("[store] warning: could not add resolved_path column: %v", err)
+	} else {
+		database.hasResolvedPath = true // detectSchema ran before column was added; fix the flag
 	}
 
 	// Load or build neighbor graph