Initial commit — Tauri image gallery with sqlite-vec

Sets up Tauri v2 + React frontend with SQLite metadata store,
sqlite-vec for CLIP embedding infrastructure, and r2d2 connection
pool replacing the single Arc<Mutex<Connection>>. Indexer now uses
rayon for parallel file metadata collection.

src-tauri/src/vector.rs

@@ -0,0 +1,60 @@
+use anyhow::{anyhow, Result};
+use rusqlite::{ffi::sqlite3_auto_extension, Connection};
+use sqlite_vec::sqlite3_vec_init;
+use std::sync::Once;
+
+pub const CLIP_MODEL_NAME: &str = "openclip-vit-b-32";
+pub const CLIP_VECTOR_DIM: usize = 512;
+
+static SQLITE_VEC_INIT: Once = Once::new();
+
+pub fn register_sqlite_vec() {
+    SQLITE_VEC_INIT.call_once(|| unsafe {
+        sqlite3_auto_extension(Some(std::mem::transmute(sqlite3_vec_init as *const ())));
+    });
+}
+
+pub fn migrate(conn: &Connection) -> Result<()> {
+    conn.execute_batch(&format!(
+        "CREATE VIRTUAL TABLE IF NOT EXISTS image_vec USING vec0(
+            image_id INTEGER PRIMARY KEY,
+            embedding FLOAT[{}] distance_metric=cosine
+        );",
+        CLIP_VECTOR_DIM
+    ))?;
+    Ok(())
+}
+
+#[allow(dead_code)]
+pub fn delete_embedding(conn: &Connection, image_id: i64) -> Result<()> {
+    conn.execute("DELETE FROM image_vec WHERE image_id = ?1", [image_id])?;
+    Ok(())
+}
+
+#[allow(dead_code)]
+pub fn upsert_embedding(conn: &Connection, image_id: i64, embedding: &[f32]) -> Result<()> {
+    if embedding.len() != CLIP_VECTOR_DIM {
+        return Err(anyhow!(
+            "expected {}-dimensional embedding, got {}",
+            CLIP_VECTOR_DIM,
+            embedding.len()
+        ));
+    }
+
+    let packed = pack_f32(embedding);
+    conn.execute("DELETE FROM image_vec WHERE image_id = ?1", [image_id])?;
+    conn.execute(
+        "INSERT INTO image_vec (image_id, embedding) VALUES (?1, ?2)",
+        (&image_id, &packed),
+    )?;
+    Ok(())
+}
+
+#[allow(dead_code)]
+fn pack_f32(values: &[f32]) -> Vec<u8> {
+    let mut out = Vec::with_capacity(values.len() * std::mem::size_of::<f32>());
+    for value in values {
+        out.extend_from_slice(&value.to_le_bytes());
+    }
+    out
+}