Put the advanced connection settings behind a disclosure

[kmcginnes]

Description

• Fetch Timeout and Neighbor Expansion Limit move into a collapsible "Advanced options" section of the connection dialog, so the common fields aren't buried.
• The section opens by itself when the connection already overrides one of them, so an existing override is never hidden.
• The trigger is a real button, so it works from the keyboard and announces whether it's expanded.
• The Fetch Timeout error message and the troubleshooting guide now point at the connection's advanced options.

Validation

• Tests that the section starts collapsed, expands on click, and opens itself for a connection with a Fetch Timeout override.
• pnpm checks and pnpm test clean on this layer.

Screenshots

A new connection starts with the advanced options collapsed.

Expanding them shows Fetch Timeout and Neighbor Expansion Limit.

Editing a connection that already sets a Fetch Timeout opens the section by itself.

Related Issues

• Part of [3.2.2][Gremlin] Relationship discovery fails with MemoryLimitExceededException for high-cardinality edge labels #2141 (split out of Ask the database for distinct edge connections instead of scanning edges #2244)
• Layer 1 of 5. Stack, bottom first: Put the advanced connection settings behind a disclosure #2278 → Show the Schema view without edge connections when their discovery fails #2277 → Sample each edge type with its own limit, 10 types per request #2279 → Ask the database for distinct edge connections instead of scanning edges #2280 → Let a connection choose how edge connections are discovered #2282

Check List

• I confirm that my contribution is made under the terms of the Apache 2.0 license.
• I have verified pnpm checks passes with no errors.
• I have verified pnpm test passes with no failures.
• I have covered new added functionality with unit tests if necessary.
• I have updated documentation if necessary.

[kmcginnes]

Approved