feat(library): Lutris + Heroic store providers (Linux)

LutrisProvider reads the local pga.db (rusqlite, read-only/immutable so a running
Lutris can't block us) → installed games, launch via `lutris lutris:rungameid/<id>`,
cover art from Lutris's on-disk cache inlined as data: URLs (no public CDN keyed by a
stable id, unlike Steam/Heroic). HeroicProvider parses Heroic's store_cache JSON —
legendary/gog/nile = Epic+GOG+Amazon in one provider — installed-only with an
install-dir existence cross-check (works around Heroic's gog is_installed bug #2691),
free public CDN cover art, launch via `heroic --no-gui heroic://launch?...` (the
single-instance-Electron gamescope-escape caveat is documented; needs live confirm).

New command_for arms (lutris_id digits-guard, heroic runner+appName-guard) + both
providers wired into all_games(); everything Linux-gated (the launchers are
Linux-only), so the Windows/macOS host build is unaffected. Deps rusqlite (bundled
SQLite, no system dep) + base64 added to the Linux target only. Unit tests with
sqlite/json fixtures (installed-only filtering, CDN-art mapping, launch guards); live
`library` enumeration returns [] gracefully on a box without the launchers.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Cargo.lock

@@ -1010,6 +1010,18 @@ dependencies = [
  "pin-project-lite",
 ]
 
+[[package]]
+name = "fallible-iterator"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2acce4a10f12dc2fb14a218589d4f1f62ef011b2d0cc4b3cb1bba8e94da14649"
+
+[[package]]
+name = "fallible-streaming-iterator"
+version = "0.1.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7360491ce676a36bf9bb3c56c1aa791658183a54d2744120f27285738d90465a"
+
 [[package]]
 name = "fastbloom"
 version = "0.14.1"
@@ -1111,6 +1123,12 @@ version = "0.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d9c4f5dac5e15c24eb999c26181a6ca40b39fe946cbe4c263c7209467bc83af2"
 
+[[package]]
+name = "foldhash"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "77ce24cb58228fbb8aa041425bb1050850ac19177686ea6e0f41a70416f56fdb"
+
 [[package]]
 name = "form_urlencoded"
 version = "1.2.2"
@@ -1586,7 +1604,16 @@ version = "0.15.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9229cfe53dfd69f0609a49f65461bd93001ea1ef889cd5529dd176593f5338a1"
 dependencies = [
- "foldhash",
+ "foldhash 0.1.5",
+]
+
+[[package]]
+name = "hashbrown"
+version = "0.16.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "841d1cc9bed7f9236f321df977030373f4a4163ae1a7dbfe1a51a2c1a51d9100"
+dependencies = [
+ "foldhash 0.2.0",
 ]
 
 [[package]]
@@ -1594,6 +1621,18 @@ name = "hashbrown"
 version = "0.17.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ed5909b6e89a2db4456e54cd5f673791d7eca6732202bbf2a9cc504fe2f9b84a"
+dependencies = [
+ "foldhash 0.2.0",
+]
+
+[[package]]
+name = "hashlink"
+version = "0.12.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a5081f264ed7adee96ea4b4778b6bb9da0a7228b084587aa3bd3ff05da7c5a3b"
+dependencies = [
+ "hashbrown 0.17.1",
+]
 
 [[package]]
 name = "heck"
@@ -1966,6 +2005,17 @@ dependencies = [
  "system-deps",
 ]
 
+[[package]]
+name = "libsqlite3-sys"
+version = "0.38.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f6c19a05435c21ac299d71b6a9c13db3e3f47c520517d58990a462a1397a61db"
+dependencies = [
+ "cc",
+ "pkg-config",
+ "vcpkg",
+]
+
 [[package]]
 name = "linux-raw-sys"
 version = "0.12.1"
@@ -2655,6 +2705,7 @@ dependencies = [
  "audiopus_sys",
  "axum",
  "axum-server",
+ "base64",
  "bytemuck",
  "cbc",
  "ffmpeg-next",
@@ -2678,6 +2729,7 @@ dependencies = [
  "rcgen",
  "reis",
  "rsa",
+ "rusqlite",
  "rustls",
  "rustls-pemfile",
  "rusty_enet",
@@ -3028,6 +3080,31 @@ dependencies = [
  "zeroize",
 ]
 
+[[package]]
+name = "rsqlite-vfs"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c51c9ae4df8a7fba42103df5c621fa3c37eccf3a3c650879e90fc48b11cc192c"
+dependencies = [
+ "hashbrown 0.16.1",
+ "thiserror 2.0.18",
+]
+
+[[package]]
+name = "rusqlite"
+version = "0.40.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "11438310b19e3109b6446c33d1ed5e889428cf2e278407bc7896bc4aaea43323"
+dependencies = [
+ "bitflags",
+ "fallible-iterator",
+ "fallible-streaming-iterator",
+ "hashlink",
+ "libsqlite3-sys",
+ "smallvec",
+ "sqlite-wasm-rs",
+]
+
 [[package]]
 name = "rustc-hash"
 version = "2.1.2"
@@ -3548,6 +3625,18 @@ dependencies = [
  "der",
 ]
 
+[[package]]
+name = "sqlite-wasm-rs"
+version = "0.5.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dc3efc0da82635d7e1ced0053bbbfa8c7ab9645d0bf36ceb4f7127bb85315d75"
+dependencies = [
+ "cc",
+ "js-sys",
+ "rsqlite-vfs",
+ "wasm-bindgen",
+]
+
 [[package]]
 name = "strsim"
 version = "0.11.1"