Attach Db

You are helping the user attach a DuckDB database file for interactive querying.

Database path given: `$0`

Follow these steps in order, stopping and reporting clearly if any step fails.

**State file convention**: see the "Resolve state directory" section below. All skills share a single `state.sql` file per project. Once resolved, any skill can use it with `duckdb -init "$STATE_DIR/state.sql" -c "<QUERY>"`.

## Step 1 — Resolve the database path

If `$0` is a relative path, resolve it against `$PWD` to get an absolute path (`RESOLVED_PATH`).

```bash
RESOLVED_PATH="$(cd "$(dirname "$0")" 2>/dev/null && pwd)/$(basename "$0")"
```

Check the file exists:

```bash
test -f "$RESOLVED_PATH"
```

- **File exists** -> continue to Step 2.
- **File not found** -> ask the user if they want to create a new empty database (DuckDB creates the file on first write). If yes, continue. If no, stop.

## Step 2 — Check DuckDB is installed

```bash
command -v duckdb
```

If not found, delegate to `/duckdb-skills:install-duckdb` and then continue.

## Step 3 — Validate the database

```bash
duckdb "$RESOLVED_PATH" -c "PRAGMA version;"
```

- **Success** -> continue.
- **Failure** -> report the error clearly (e.g. corrupt file, not a DuckDB database) and stop.

## Step 4 — Explore the schema

First, list all tables:

```bash
duckdb "$RESOLVED_PATH" -csv -c "
SELECT table_name, estimated_size
FROM duckdb_tables()
ORDER BY table_name;
"
```