Count auto-tapped mana toward Expend

[matthewevans]

Summary

• Use the authoritative cast-payment mana stamp when finalizing a spell, including auto-tapped mana produced and spent between pool snapshots.
• Remove the obsolete snapshot from deferred cast resumption.
• Add a Bakersbane Duo regression covering an automatically paid four-mana spell.

Validation

• Tilt clippy: green.
• Tilt test-engine: 23,687 passed, including issue_7232_expend_auto_land_payment.

Closes #7232.

Summary by CodeRabbit

• Bug Fixes

  • Corrected casting-cost tracking to accurately include mana paid through automatically tapped lands.
  • Fixed Expend-related effects so they recognize the full mana amount used to cast a spell.
  • Improved deferred and alternate payment handling for spell costs.

• Tests

  • Added integration coverage confirming that auto-tapped land mana correctly contributes to Expend bonuses.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro Plus

Run ID: 2061f03d-3fd6-4ca0-afd3-c21bd22f89a6

📥 Commits

Reviewing files that changed from the base of the PR and between 678d198 and 8606308.

📒 Files selected for processing (4)

• crates/engine/src/game/casting_costs.rs
• crates/engine/src/types/game_state.rs
• crates/engine/tests/integration/issue_7232_expend_auto_land_payment.rs
• crates/engine/tests/integration/main.rs

💤 Files with no reviewable changes (1)

• crates/engine/src/types/game_state.rs

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📝 Walkthrough

Walkthrough

Casting-cost tracking now reads mana recorded on the spell object. Pool-snapshot tracking was removed from pending cast state and deferred payment paths. A new integration test verifies that auto-tapped lands count toward Expend.

Changes

Mana payment tracking

Layer / File(s)	Summary
Recorded payment authority crates/engine/src/game/casting_costs.rs	Cast finalization uses the spell object's recorded mana amount instead of subtracting mana-pool snapshots.
Deferred payment state crates/engine/src/game/casting_costs.rs, crates/engine/src/types/game_state.rs	Pending cast state no longer stores pool_before. Deferred payment paths use recorded spell payment amounts.
Auto-tapped land validation crates/engine/tests/integration/issue_7232_expend_auto_land_payment.rs, crates/engine/tests/integration/main.rs	The integration suite verifies Expend tracking for a spell paid with four auto-tapped lands and checks Bakersbane Duo's +1/+1 effect.

Estimated code review effort: 3 (Moderate) | ~20 minutes

Possibly related PRs

• phase-rs/phase#6331: Adds mana provenance and recording used by casting-cost tracking.
• phase-rs/phase#6352: Updates cast-payment tracking across copies and zone changes.
• phase-rs/phase#7007: Modifies auto-payment and deferred payment handling.

Suggested labels: bug

Suggested reviewers: lgray, jacobwoodson, andriypolanski

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly describes the main change: counting auto-tapped mana toward Expend.
Linked Issues check	✅ Passed	The changes use recorded payment amounts, remove the faulty snapshot logic, and add regression coverage for issue #7232.
Out of Scope Changes check	✅ Passed	All changes directly support the Expend fix and its regression test; no unrelated code changes are present.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch agent/on-deck-expend-auto-payment

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[github-actions]

Generated for head 860630816352523affb9ec91ac8016a0d7f0eaa5.

Parse changes introduced by this PR

✓ No card-parse changes detected.