fix: structured config with create_if_missing for non-existent database (#50)

When using structured database config, the `name` field was included in
the initial connection string. If the target database did not exist yet
(and a phase had `create_if_missing: true`), the connection failed before
the create phase could run.

Now initium detects this scenario and first connects to the driver's
default admin database (`postgres` / `mysql`), creates the missing
database, then reconnects to the target for full execution.

Also adds integration tests for structured config edge cases:
special-character passwords, PostgreSQL options field, and the
create_if_missing regression.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: mikkeldamsgaard

CHANGELOG.md

@@ -7,6 +7,14 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Fixed
+
+- Structured database config now works with `create_if_missing: true` when the target database does not yet exist. Previously, the initial connection included the non-existent database name, causing an immediate connection error. Now initium connects to the driver's default admin database (`postgres` / `mysql`) first, creates the target, then reconnects. Fixes [#50](https://github.com/KitStream/initium/issues/50).
+
+### Chores
+
+- Added integration tests for structured database connectivity: special-character passwords (URL-reserved chars like `@`, `:`, `/`, `?`, `#`, `%`), PostgreSQL `options` field (`connect_timeout`), and `create_if_missing` with non-existent database ([#50](https://github.com/KitStream/initium/issues/50)).
+
 ## [2.0.1] - 2026-03-14
 
 ### Fixed

src/seed/mod.rs

@@ -5,6 +5,14 @@ pub mod schema;
 
 use crate::logging::Logger;
 
+fn default_admin_database(driver: &str) -> String {
+    match driver {
+        "postgres" | "postgresql" => "postgres".into(),
+        "mysql" => "mysql".into(),
+        _ => String::new(),
+    }
+}
+
 fn render_template(content: &str) -> Result<String, String> {
     let env_map: std::collections::HashMap<String, String> = std::env::vars().collect();
     let mut jinja_env = minijinja::Environment::new();
@@ -41,6 +49,44 @@ pub fn run(
     let tracking_table = plan.database.tracking_table.clone();
     let driver = plan.database.driver.clone();
 
+    // When using structured config and a phase needs to create a database that
+    // matches the configured name, we must first connect without the database
+    // name (to the driver's default database), create the target, then
+    // reconnect. See https://github.com/KitStream/initium/issues/50
+    let needs_bootstrap = plan.database.has_structured_config()
+        && plan.phases.iter().any(|p| {
+            p.create_if_missing && !p.database.is_empty() && p.database == plan.database.name
+        });
+
+    if needs_bootstrap {
+        let mut admin_config = plan.database.clone();
+        admin_config.name = default_admin_database(&admin_config.driver);
+
+        log.info(
+            "connecting to default database for bootstrap",
+            &[("driver", driver.as_str())],
+        );
+        let mut admin_db = db::connect(&admin_config)?;
+
+        for phase in &plan.phases {
+            if phase.create_if_missing && !phase.database.is_empty() {
+                log.info(
+                    "creating database if missing",
+                    &[("database", phase.database.as_str())],
+                );
+                admin_db.create_database(&phase.database)?;
+            }
+            if phase.create_if_missing && !phase.schema.is_empty() {
+                log.info(
+                    "creating schema if missing",
+                    &[("schema", phase.schema.as_str())],
+                );
+                admin_db.create_schema(&phase.schema)?;
+            }
+        }
+        drop(admin_db);
+    }
+
     log.info("connecting to database", &[("driver", driver.as_str())]);
 
     let db = db::connect(&plan.database)?;