Add cross-platform notification audio cues

[Guffawaffle]

Adds configurable audio cues for victory, defeat, armada creation, armada victory and armada defeat.

[audio]
alert_victory = "success"
alert_defeat = "warning"
alert_armada_created = "info"
alert_armada_battle_won = "success"
alert_armada_battle_lost = "warning"

Each defaults to none, preserving current behavior. Supported cues are default, info, success, warning, alarm, arrival, soft, ping, and repair.

Reuses the existing toast observer. Both platforms use generated in-memory audio: Windows plays through PlaySoundW, and macOS through NSSound. macOS playback and callback-thread behavior still need runtime verification.

Mac ARM integration smoke confirmed notification audio on the combined build. Intel Mac runtime testing remains unconfirmed; this is supporting integration evidence, not a new standalone artifact qualification.

Refreshed against current dev (e7a646b5) in 1cebd68b. The config conflict resolution preserves the five disabled-by-default audio cues and upstream's independent hook-install controls. Audio playback and platform wiring are unchanged.

Validation for this head: Windows release build, all 11 example TOML parses, semantic example comparison, and diff check pass. Three independent reviews found no actionable defect in the refresh. Fresh Windows/macOS CI will validate the updated head; existing standalone playback and Mac callback-thread qualification gaps remain.

[Guffawaffle]

Evidence-first review is complete at 218c594 (receipt 7471468cc998d67bf625ad143d711c8ed8a6923cb4e95ad366bbbc694ccb03e2).

All three lanes found no confirmed code defect. The config/default/example mappings, static WAV lifetime, platform guards, and Windows/macOS build wiring survived review. A fresh local Windows release mods build and diff-check also pass.

The gate remains evidence-incomplete rather than code-failed: actual enabled-cue playback has not been observed on exact Windows/macOS artifacts, and macOS thread affinity should be confirmed under rapid delivery. The current client native code shows EnqueueToast and EnqueueOrCombineToast as parallel implementations, so duplicate playback is not presently substantiated; one-cue-per-event should still be included in runtime verification.

[Guffawaffle]

Refreshed against current dev (0b1c490) in merge commit 43284c9. Resolved the ten localized-example conflicts by preserving the refreshed dev content and all five audio settings with their none defaults. Audio implementation and platform wiring are unchanged from the previous PR head.

Validation: all 11 example TOMLs parse; a semantic comparison verifies each localized example is dev plus exactly the five disabled audio alerts; exact-head Windows release build and PR diff-check pass. All three merge-focused review lanes found no regression. Existing runtime/macOS playback evidence gates remain unchanged; fresh CI will validate this merge head.