fix: add missing ai_providers columns and fix linux-amd64 build

- Add migration 015 to add use_datastore_upload and created_at columns
- Handle column-already-exists errors gracefully
- Update Dockerfile to install linuxdeploy for AppImage bundling
- Add fuse dependency for AppImage support

.docker/Dockerfile.linux-amd64

@@ -2,7 +2,7 @@
 # All system dependencies are installed once here; CI jobs skip apt-get entirely.
 # Rebuild when: Rust toolchain version changes, webkit2gtk/gtk major version changes,
 # Node.js major version changes, OpenSSL major version changes (used via OPENSSL_STATIC=1),
-# or Tauri CLI version changes that affect bundler system deps.
+# Tauri CLI version changes that affect bundler system deps, or linuxdeploy is needed.
 # Tag format: rust<VER>-node<VER>
 FROM rust:1.88-slim
 
@@ -20,9 +20,14 @@ RUN apt-get update -qq \
        perl \
        jq \
        git \
+       fuse \
     && curl -fsSL https://deb.nodesource.com/setup_22.x | bash - \
     && apt-get install -y --no-install-recommends nodejs \
     && rm -rf /var/lib/apt/lists/*
 
+# Install linuxdeploy for AppImage bundling (required for Tauri 2.x)
+RUN curl -fsSL https://github.com/tauri-apps/linuxdeploy/releases/download/continuous/linuxdeploy-x86_64.AppImage -o /usr/local/bin/linuxdeploy \
+    && chmod +x /usr/local/bin/linuxdeploy
+
 RUN rustup target add x86_64-unknown-linux-gnu \
     && rustup component add rustfmt clippy

src-tauri/src/db/migrations.rs

@@ -191,6 +191,11 @@ pub fn run_migrations(conn: &Connection) -> anyhow::Result<()> {
                 updated_at TEXT NOT NULL DEFAULT (datetime('now'))
             );",
         ),
+        (
+            "015_add_ai_provider_missing_columns",
+            "ALTER TABLE ai_providers ADD COLUMN use_datastore_upload INTEGER DEFAULT 0;
+             ALTER TABLE ai_providers ADD COLUMN created_at TEXT NOT NULL DEFAULT (datetime('now'));",
+        ),
     ];
 
     for (name, sql) in migrations {
@@ -201,9 +206,20 @@ pub fn run_migrations(conn: &Connection) -> anyhow::Result<()> {
 
         if !already_applied {
             // FTS5 virtual table creation can be skipped if FTS5 is not compiled in
+            // Also handle column-already-exists errors for migration 015
             if let Err(e) = conn.execute_batch(sql) {
                 if name.contains("fts") {
                     tracing::warn!("FTS5 not available, skipping: {e}");
+                } else if *name == "015_add_ai_provider_missing_columns" {
+                    // Skip error if columns already exist (e.g., from earlier migration or manual creation)
+                    let err_str = e.to_string();
+                    if err_str.contains("duplicate column name")
+                        || err_str.contains("has no column named")
+                    {
+                        tracing::info!("Columns may already exist, skipping migration 015: {e}");
+                    } else {
+                        return Err(e.into());
+                    }
                 } else {
                     return Err(e.into());
                 }
@@ -560,4 +576,86 @@ mod tests {
         assert_eq!(encrypted_key, "encrypted_key_123");
         assert_eq!(model, "gpt-4o");
     }
+
+    #[test]
+    fn test_add_missing_columns_to_existing_table() {
+        let conn = Connection::open_in_memory().unwrap();
+
+        // Simulate existing table without use_datastore_upload and created_at
+        conn.execute_batch(
+            "CREATE TABLE IF NOT EXISTS ai_providers (
+                id TEXT PRIMARY KEY,
+                name TEXT NOT NULL UNIQUE,
+                provider_type TEXT NOT NULL,
+                api_url TEXT NOT NULL,
+                encrypted_api_key TEXT NOT NULL,
+                model TEXT NOT NULL,
+                max_tokens INTEGER,
+                temperature REAL,
+                custom_endpoint_path TEXT,
+                custom_auth_header TEXT,
+                custom_auth_prefix TEXT,
+                api_format TEXT,
+                user_id TEXT,
+                updated_at TEXT NOT NULL DEFAULT (datetime('now'))
+            );",
+        )
+        .unwrap();
+
+        // Verify columns BEFORE migration
+        let mut stmt = conn.prepare("PRAGMA table_info(ai_providers)").unwrap();
+        let columns: Vec<String> = stmt
+            .query_map([], |row| row.get::<_, String>(1))
+            .unwrap()
+            .collect::<Result<Vec<_>, _>>()
+            .unwrap();
+
+        assert!(columns.contains(&"name".to_string()));
+        assert!(columns.contains(&"model".to_string()));
+        assert!(!columns.contains(&"use_datastore_upload".to_string()));
+        assert!(!columns.contains(&"created_at".to_string()));
+
+        // Run migrations (should apply 015 to add missing columns)
+        run_migrations(&conn).unwrap();
+
+        // Verify columns AFTER migration
+        let mut stmt = conn.prepare("PRAGMA table_info(ai_providers)").unwrap();
+        let columns: Vec<String> = stmt
+            .query_map([], |row| row.get::<_, String>(1))
+            .unwrap()
+            .collect::<Result<Vec<_>, _>>()
+            .unwrap();
+
+        assert!(columns.contains(&"name".to_string()));
+        assert!(columns.contains(&"model".to_string()));
+        assert!(columns.contains(&"use_datastore_upload".to_string()));
+        assert!(columns.contains(&"created_at".to_string()));
+
+        // Verify data integrity - existing rows should have default values
+        conn.execute(
+            "INSERT INTO ai_providers (id, name, provider_type, api_url, encrypted_api_key, model)
+             VALUES (?, ?, ?, ?, ?, ?)",
+            rusqlite::params![
+                "test-provider-2",
+                "Test Provider",
+                "openai",
+                "https://api.example.com",
+                "encrypted_key_456",
+                "gpt-3.5-turbo"
+            ],
+        )
+        .unwrap();
+
+        let (name, use_datastore_upload, created_at): (String, i64, String) = conn
+            .query_row(
+                "SELECT name, use_datastore_upload, created_at FROM ai_providers WHERE name = ?1",
+                ["Test Provider"],
+                |r| Ok((r.get(0)?, r.get(1)?, r.get(2)?)),
+            )
+            .unwrap();
+
+        assert_eq!(name, "Test Provider");
+        assert_eq!(use_datastore_upload, 0);
+        assert!(created_at.len() > 0);
+    }
 }