[Reconciliation] Billing, usage and pricing #322

Parent epic: #318

Outcome

Make pricing handoffs, credit units, payment settings and usage line items consistent and verifiable.

Child tickets

• [Reconciliation][P2] Preserve the selected Platform billing period through the purchase handoff #338 — P2: Preserve the selected Platform billing period through the purchase handoff
• [Reconciliation][P2] Make top-up schemas and examples satisfy the current request validator #342 — P2: Make top-up schemas and examples satisfy the current request validator
• [Reconciliation][P2] Align card removal with the documented auto-top-up and fallback semantics #343 — P2: Align card removal with the documented auto-top-up and fallback semantics
• [Reconciliation][P2] Complete the credits and subscription schema migration to three plans #344 — P2: Complete the credits and subscription schema migration to three plans
• [Reconciliation][P2] Prevent tied-timestamp charge loss and reconcile the usage response schema #345 — P2: Prevent tied-timestamp charge loss and reconcile the usage response schema
• [Reconciliation][P2] Reconcile billed feature coverage and social-scrape micro-dollar prices #346 — P2: Reconcile billed feature coverage and social-scrape micro-dollar prices
• [Reconciliation][P2] Reconcile credit-shortfall recovery across research, content and catalog skills #350 — P2: Reconcile credit-shortfall recovery across research, content and catalog skills

Completion

• Each child has a linked correction or explicit owner-approved disposition with its rationale.
• Changes land through the owning repository release workflow; related existing issues and PRs retain their original scope.
• Published or installed behavior is read back where required; source, tests, merge, deployment and user-flow verification are recorded separately.
• Dependencies on another workstream are linked and no duplicated implementation project is created.