feat(assets): accept both depot filename schemas in the GUI resolver

[AprilNEA]

What

Teach the asset resolver and the two sync paths to accept both depot
filename schemas Logi ships, instead of hardcoding the newer *_core names:

slot	newer depots	older depots
hotspot metadata	core_metadata.json	metadata.json
hero render	front_core.png	front.png
buttons render	side_core.png	side.png

A depot commits to one schema or the other; each slot now resolves to
whichever filename the depot's index.json entry actually lists. The
manifest.json (device_image / device_buttons_image) already maps to
the concrete render, so colour-variant resolution is unchanged.

Why

The full asset mirror now hosts every Logi Options+ device, but the older
schema covered most keyboards, the MX Vertical, and the older mice.
The GUI gated on core_metadata.json + front_core.png literally, so
those depots fell through to the synthetic silhouette even though their
assets were present.

Changes

• openlogi-assets: replace the CORE_FILES const with METADATA_FILES
  / FRONT_RENDER_FILES / BUTTONS_RENDER_FILES preference lists plus
  DeviceEntry::{preferred_file, baseline_files}.
• GUI resolver (asset/mod.rs): probe both metadata names on disk and
  fall through both render schemas before giving up.
• GUI + CLI sync: fetch the per-depot baseline in whichever schema the
  depot ships; warn (don't error) when a depot has no metadata/render.

Testing

• cargo fmt --check, cargo clippy --workspace --all-targets -- -D warnings, cargo test --workspace — all green.
• New unit tests: baseline_files resolution for core/old/missing schemas,
  plus an end-to-end load_files test that resolves an old-schema depot
  (metadata.json + front.png, no manifest) from a temp dir.

Note

MX Vertical now renders fully (it has a device_buttons_image, so hotspots
work). Keyboards render their hero image, but their key-level hotspots live
under a different metadata image key (device_keys_image) and need a
keyboard button model — that stays a separate feature.

[pullfrog]

ℹ️ One stale comment reference — everything else is clean.

Reviewed changes — The GUI resolver and both sync paths now accept both Logi depot filename schemas (*_core and bare names) via preference-list constants and a new DeviceEntry::preferred_file/baseline_files API, fixing GUI rendering for MX Vertical and older depots.

• Add METADATA_FILES, FRONT_RENDER_FILES, BUTTONS_RENDER_FILES — Preference-list constants replacing the single CORE_FILES array, one per schema slot
• Add DeviceEntry::preferred_file — Resolves a schema slot to the first matching filename in the depot's registry
• Add DeviceEntry::baseline_files — Composes the per-depot baseline (metadata + manifest + hero render) with optional slots
• Update GUI resolver — Probes both metadata names on disk; fallback chain includes both schema names for each render slot
• Update CLI and GUI sync — Use baseline_files() and preferred_file() instead of hardcoded constants
• Update is_optional_asset — Accepts both front_ext and front_ext_ prefixes for colour variants
• New unit tests — baseline_files resolution for core/old/missing schemas, plus end-to-end load_files test with old-schema depot

---

Note: 1 inline comment(s) dropped because they did not anchor to lines inside the PR diff:

• crates/openlogi-gui/src/asset/sync.rs:125 (RIGHT) — line 125 (RIGHT) is not inside a diff hunk

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[pullfrog]

Quick follow-up: the dropped inline was about a stale comment at crates/openlogi-gui/src/asset/sync.rs:125 that still references CORE_FILES (removed in this PR). Not blocking — worth updating when you touch this file next.

  ^{｜ View workflow run ｜ via Pullfrog ｜ Using Big Pickle (free) (credentials for Anthropic not configured) ｜ 𝕏}