refactor(bookings): add round-robin host effective-limits foundation and flow wiring

[manurana26770]

What does this PR do?

This PR introduces the first foundation slice for per-member round-robin limit settings without changing current booking behavior.

• Fixes Enable limit settings on an individual member basis in round-robin events #27401
• Fixes CAL-7149

What changes

• Adds a reusable resolver for round-robin host effective limits with clear precedence:
  • host override when present
  • event-level fallback when not
• Adds deterministic bucketing for hosts that share the same effective limit profile.
• Adds a typed helper to extract host-level override values for future schema-backed fields.
• Wires the bucketing foundation into the regular booking flow without changing current behavior.
• Adds unit tests for precedence, bucketing, and override extraction behavior.
• Adds deduplicates host normalization/projection logic in the routing layer by centralizing repeated mapping into a shared path, reducing drift risk without intended behavior change.
• Adds host-level round-robin override fields end-to-end through data retrieval, typed transport, and routing normalization so overrides can flow into booking logic.
• Persistence support for those overrides by updating the Prisma schema and adding a migration, enabling database-level storage for per-host limit override fields.

Visual Demo (For contributors especially)

N/A for this foundation PR. The change is internal plumbing and does not introduce a user-facing UI change yet.

Mandatory Tasks (DO NOT REMOVE)

• I have self-reviewed the code.
• I have updated the developer docs in /docs if this PR makes changes that would require a documentation change. N/A
• I confirm automated tests are in place that prove my fix is effective or that my feature works.

How should this be tested?

This PR is a foundation slice, so testing focuses on behavior preservation and contract validation.

• Run the targeted unit tests:
  • yarn vitest run packages/features/bookings/lib/handleNewBooking/test/resolveRoundRobinHostEffectiveLimits.test.ts
  • yarn vitest run packages/features/bookings/lib/handleNewBooking/test/computeTeamData.test.ts
  • yarn vitest run packages/features/bookings/lib/handleNewBooking/test/round-robin-no-hosts.test.ts
  • yarn vitest run packages/features/users/lib/getRoutedUsers.test.ts
• Expected result:
  • Event-level limits remain the default source of truth.
  • Host override values are resolved only for round-robin hosts.
  • When no host overrides exist, behavior stays exactly the same as before.
  • Routing host normalization preserves override fields consistently across relevant paths.

Checklist

• My code follows the style guidelines of this project.
• I have commented my code, particularly in hard-to-understand areas.
• I have checked that my changes generate no new warnings.
• My PR is small and focused.

[CLAassistant]

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[cubic-dev-ai]

No issues found across 3 files

[cubic-dev-ai]

1 issue found across 6 files (changes from recent commits).

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="packages/features/users/lib/getRoutedUsers.ts">

<violation number="1" location="packages/features/users/lib/getRoutedUsers.ts:127">
P2: Large duplicated host-projection logic across booking paths increases drift risk for override/effective-limit fields.</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review, or fix all with cubic.}

[manurana26770]

@CarinaWolli could you plz review or tell anybody to review this.
I'm working on this and will be raising more PRs.