Document array attributes and targeting operators

[roncohen]

Summary

• Add an array-attributes guide with examples, update and empty-list behavior, storage limits, and keys Reflag ignores.
• Explain all eight array operators. Clearly separate finding a value with CONTAINS/ANY_OF from requiring a one-item array with IS.
• Explain how to send contextJson, use the older query format for single values, and read evaluationErrors.
• Link from access rules, targeting concepts, filters, API reference, and navigation.
• Use plain words, shorter sections, and concrete examples. Remove repeated operator lists and the unclear missing-field caveat. Keep missing-field and unsupported-operator warnings clearly about flag access.
• No SDK documentation files changed.

Publish after rollout

Evaluator 1.1.1 is released. Keep this draft until https://github.com/reflagcom/web/pull/3605 is deployed and the contextJson SDK transport in reflagcom/javascript#712 is released.

Checks

• 10 added/changed relative links resolve, including heading links.
• Two new JSON examples parse; GitBook blocks are balanced.
• The contextJson JavaScript example runs with a mocked fetch and preserves arrays.
• 40 documented checks pass against the released evaluator 1.1.1.
• git diff --check passes.
• This docs repository has no build or test scripts.

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