ai agent onboarding

[naefp]

onboard to project. take a look at other client library implementations as reference (bexioapinet, cashctrlapinet) and the lates ai-cockpit docs/knowledge.

[AMANDA-Info]

@naefp — onboarding complete. PR #2 is ready for review.

What was created:

• CLAUDE.md — AI team instructions (stack, structure, build/test commands, conventions, workflow hints)
• ai_instructions.md — strict procedural rules for AI agents (architecture, DTO/serialization patterns, testing constraints, forbidden patterns, persona routing)

Both files were modelled after BexioApiNet and CashCtrlApiNet and tailored to WebSmsNet's actual implementation. The doc-writer agent verified accuracy against the source code.

Notable findings flagged for follow-up (not in scope for this PR):

• WebSmsNet uses xUnit + FluentAssertions; the org default is NUnit + Shouldly — consider aligning in a dedicated ticket
• NuGet packages are missing PackageReadmeFile — consider adding in a follow-up