docs: document two Apollo API quirks (accounts filter drop, update_roles payload)

[jschfflr]

Adds two entries to the "API Quirks" section of CLAUDE.md so they aren't rediscovered later:

• accounts/search silently drops unknown filter keys → returns an unfiltered default page that looks like a real match (the bug behind fix: validate search_accounts filters (raise on unknown keys) #14). Notes the search_accounts allowlist guard and that the same risk applies to other search_* methods.
• opportunities/update_roles needs the role type nested under a role array → flat shape 422s with undefined method 'map' for nil (the bug behind fix: nest role type in update_opportunity_roles payload (unbreak set-role) #15). Documents the correct wire shape and that update_opportunity_roles reshapes flat entries.

Docs-only; no code change.

🤖 Generated with Claude Code

[peqy]

Looks good. These two quirks are documented clearly (including the concrete failure modes and the client-side guards/reshaping), which should prevent reintroducing #14/#15. Ship it.