fix: Deduplicate FTS entries across catalog parts in build_shards

build_shards() iterates all three catalog parts (base, dependency,
summary) and each lists the same packages, causing every stem to be
inserted into the FTS index 3 times. Track seen stems in a HashSet
and skip duplicates. Fixes #22.

libips/src/repository/sqlite_catalog.rs

@@ -193,6 +193,10 @@ pub fn build_shards(
         .map_err(|e| ShardBuildError::new(format!("Failed to create catalog manager: {}", e)))?;
     let mut package_count = 0usize;
     let mut package_version_count = 0usize;
+    // Track which packages have been inserted into FTS to avoid duplicates.
+    // The catalog has multiple parts (base, dependency, summary) that each
+    // list the same packages — we only want one FTS entry per stem.
+    let mut fts_seen: std::collections::HashSet<String> = std::collections::HashSet::new();
 
     // Begin transactions for batch inserts
     let active_tx = active_conn.transaction()?;
@@ -332,7 +336,10 @@ pub fn build_shards(
                             }
                         }
 
-                        // Extract summary and description for FTS
+                        // Extract summary and description for FTS (deduplicate
+                        // across catalog parts — base, dependency, and summary
+                        // parts all list the same packages)
+                        if fts_seen.insert(pkg_name.clone()) {
                             let summary = manifest
                                 .attributes
                                 .iter()
@@ -359,6 +366,7 @@ pub fn build_shards(
                 }
             }
         }
+    }
 
     // Commit transactions
     active_tx.commit()?;