Add A Backend

Adding a backend should keep backend-specific behavior behind the existing seams instead of spreading switch logic through commands.

Decide The Backend Shape

Before writing code, define:

• Connection options such as host, port, user, account, or path.
• Runtime context keys such as database, schema, warehouse, or role.
• secrets references such as password env vars or key passphrase env vars.
• Inspect capabilities that are real for the backend.
• Statement actions that tonic should authorize and forward.

Do not fake catalog, namespace, or DDL support just to match another backend.

Main Code Paths

Area	Files
Config model	internal/config/config.go, internal/config/config_test.go
Backend open/summary	internal/backend/
Target resolution	internal/target/target.go
Connections CLI	cmd/connections_add.go, cmd/connections_show.go
Query execution	internal/queryexec/
Inspect runtime	internal/dbinspect/
CLI inspect wiring	cmd/inspect_*.go

Implementation Order

1. Add config parsing, normalization, validation, YAML marshal/decode support, and tests.
2. Register a backend implementation in internal/backend.
3. Verify target resolution and secret loading.
4. Add connections add <backend> NAME CLI support.
5. Confirm query execution works through database/sql and backend context application.
6. Register inspect support or explicit unsupported errors.
7. Add real tests where practical.
8. Update docs and the command reference.

Live Checks

Run realistic commands before calling a backend done:

go run . connections add <backend> <name> ...
go run . connections show <name>
go run . query ping --target <name>
go run . query exec --target <name> --sql 'select 1'
go run . inspect tables --target <name>
go run . query exec --file path.sql

Finish with:

go test ./...