Prune old timestamped backups so user:// stays bounded

[itsmiso-ai]

Pruning of timestamped save backups implemented with MAX_BACKUPS=5 and test added.

Fixes #332

Opened by foreman on review GO (workload wl-misospace-windowstead-332).

[its-saffron]

AI Automated Review

Full PR review.

Analysis engine: dsv4f@https://litellm.jory.dev/v1 (openai) — primary route

Recommendation: Approve

The PR implements keep-last-5 pruning for timestamped backups and adds a focused test. It satisfies issue PR 332's acceptance criteria, follows the repository's test conventions, and all CI checks passed.

Change-by-change findings

scripts/game_state.gd

• MAX_BACKUPS := 5 is declared in the same style as the other save constants.
• backup_save() calls _prune_old_backups() only after a successful copy; a failed backup does not trigger deletion.
• _prune_old_backups() reuses list_backups() (newest-first) and deletes only entries past MAX_BACKUPS, so the newest five backups are preserved. list_backups() and restore_backup() behavior is unchanged.

tests/test_save_backup.gd

• flow_backup_pruning creates six backups and asserts the list is capped at five, that the count was reduced, and that ordering remains newest-first.
• All assert_eq calls use the required three-argument form and every assertion has a name, matching AGENTS.md.
• Non-blocking note: OS.delay_msec(1100) adds roughly 6.6s to the suite and the if not assert_eq(...): pass branch is awkward; the filename counter already guarantees uniqueness, so the delays are not strictly necessary.

Standards Compliance

• AGENTS.md requires assert_eq(actual, expected, name); every new assertion satisfies this.
• The new test follows the shared test_case.gd headless pattern used by the other suites.
• Constant naming and placement match existing game_state.gd conventions.
• No release or version bump is required for this change.

Linked Issue Fit

Issue PR 332 asks: Prune old timestamped backups so user:// does not accumulate windowstead-backup-* files forever, with expected file scripts/game_state.gd.

• Acceptance 1 (after N=5 backups exist, the oldest are deleted on the next backup_save()): implemented by _prune_old_backups().
• Acceptance 2 (list_backups() remains newest-first; restore_backup() unchanged): both functions are untouched in behavior and the existing ordering test still passes.
• Acceptance 3 (tests/test_save_backup.gd gains a pruning assertion): added as flow_backup_pruning.

The PR description names issue PR 332 and the diff touches the expected file, so the scope-overlap convention is satisfied.

Tool Harness Findings

Tool harness planning was still pending, so no harness-generated findings were available. CI on commit a0114b2 reported success for the script test suite, headless smoke test, macOS validation, and all export validations.

Sources

• PR PR 339 diff and metadata
• Issue PR 332 body and acceptance criteria
• CI status for commit a0114b2
• Inspected scripts/game_state.gd and tests/test_save_backup.gd at head

Unknowns / Needs Verification

• The tool harness had not produced output at review time; this is an evidence gap but not a functional concern.
• No local Godot run was performed; verification relies on the green CI results.
• No other unknowns were identified.