docs(dsl): document outgoing as the default neighbors direction

What does this MR do and why?

A neighbors query without a direction returns only relationships that start at the center node, but the query schema says the default is both directions, so agents that rely on the default silently miss every incoming relationship. This makes the schema and the query language guide state the default the server applies.

Related Issues

Closes #1330

Testing

Before, the neighbors direction description the schema serves: "Traversal direction (default: both)." with a default of both. After: "Traversal direction (default: outgoing)." with a default of outgoing. The guide's neighbors section gains a table with both fields.

Checked locally: markdownlint-cli2 0.22.1 with this repository's configuration reports no errors on the changed Markdown; Vale with .vale.ini reports no errors and no new warnings; scripts/linting/prose_lint.py passes on the skill files; the schema is valid JSON; and the skill copy is byte-identical to the guide, which is what mise run skill:sync:orbit produces. I did not run lychee, and the change adds no links.

Performance Analysis

Text and a declared default only: no query is accepted, rejected or answered differently.

• This merge request does not introduce any performance regression. If a performance regression is expected, explain why.

Agent context: long-form analysis, file-by-file walkthroughs, profiler output, alternatives considered

[skip pinned-version-check]: the check asks for a query_dsl bump because config/schemas/graph_query.schema.json changes. Besides the description, the declared default of direction changes from both to outgoing, which is the default the compiler already applies, so no query is accepted, rejected or answered differently. If you read the declared default as part of the contract and would rather have a bump, I will add one.

Files:

• config/schemas/graph_query.schema.json: NeighborsConfig.direction description and default.
• docs/source/remote/queries/query-language.md, Neighbors: a field table with direction (default outgoing) and rel_types (default all types), and one sentence on getting incoming relationships.
• skills/orbit/references/query_language.md: synced from the guide.
• skills/orbit/SKILL.md: version 0.33.2, one above the 0.33.1 that main has from !2650 (merged). The CLI caches the skill by version, so the same version must not ship different content. Since !2692 (merged) the server tests read the expected version from the skill itself, so no test changes with it.
• skills/orbit/SKILL.gql.md: version 0.33.2+gql, the JSON version plus +gql, as references/maintaining.md asks and gql_callers_get_the_gql_manifest checks. Nothing else in the GQL skill changes: GQL mode does not serve query_language.md, and a GQL pattern always spells its direction, with -- for both.

The compiler's default is Outgoing in Direction, read through #[serde(default)] on the neighbors input. Measured on GitLab.com: with no direction, a project's neighbors are only its branches; with both, the group, creator and labels appear too.