Implement or remove nonfunctional Stardew configuration options

[Exohayvan]

Summary

The Stardew configuration exposes emc_on_hud, creative_items, and mode, but those values are not used by gameplay code.

Evidence

• StardewModConfig parses and documents EmcOnHud, CreativeItems, and Mode.
• Repository-wide C# usage shows these values only in configuration and analytics capture.
• Difficulty affects recipe generation and PrivateEmc affects state ownership, demonstrating the expected configuration pattern.
• CreativeItems is especially misleading because item eligibility/value paths currently do not enforce it.

Impact

Players can change documented settings and restart without any gameplay effect, while telemetry records the selected value as if it were active.

Reproduction / verification

• Toggle each setting independently and exercise the advertised behavior.
• Confirm whether the intended feature exists or the setting should be removed/deprecated.

Proposed direction

Define and implement each option's behavior with tests, or remove it from generated configuration and telemetry until supported. Coordinate CreativeItems enforcement with the Stardew EMC eligibility issue.

Acceptance criteria

• Every shipped config option has documented, observable behavior.
• Unsupported options are removed or clearly deprecated.
• Telemetry reports only implemented configuration behavior.
• Tests verify each retained option.

Audit provenance

Candidate #27 from the read-only repository audit performed on 2026-07-20. This is separate from existing issues #3, #4, #25, and #27 unless explicitly linked later.