Document connecting to a local database without TLS

[openai0229]

What

The "First connection and query" section only showed PostgreSQL and mentioned --tls disable in passing, so the black-box run against four local containers had nothing to follow when every default connection failed on a self-signed certificate.

• Names the equivalent flags for MySQL, Oracle and SQL Server.
• States the three failure messages a local container produces under the default verify-full: invalid peer certificate: UnknownIssuer (MySQL), error performing TLS handshake (PostgreSQL) and a closed connection (Oracle).
• Adds a copyable MySQL example with --tls disable and the datasource update form for an existing connection.
• Notes that the error message repeats the option when a connection fails before any statement, which 0.1.7 added.

Verification

• Documentation only; code fences balanced (44 markers) and the section renders as three paragraphs plus two code blocks.
• The described behaviour matches the released 0.1.7 run against MySQL 8.4, PostgreSQL 17, Oracle 23 Free and azure-sql-edge.

Risks and limits

• Documents --tls disable as the local-container workaround; a certificate the machine trusts remains the better choice for anything reachable over a network.