Replace per-emulator boolean flags with a shared emulator registry

[misantronic]

Replaces the 18 parallel *Installed / *Enabled booleans (and the fan-out they forced on every caller) with a single Emulator enum that carries everything per-emulator: display name, label, prefs keys, package candidates, and how it gets patched.

Net +902 / −2244; MainViewModel drops from 3029 to ~2300 lines. Adding an emulator is now one enum entry plus its four string resources.

Structure

Emulator describes each emulator, with two mutually exclusive patch mechanisms:

• ConfigOverride — RetroArch, Dolphin, PPSSPP. Patched by rewriting their config files (SAF, or the Shizuku user service). Holds the hardcore/patched prefs keys, SAF-uri loader, hardcore detector, patch/revert functions, and the Shizuku wire key.
• BroadcastOverride — ARMSX1, ARMSX2, Flycast, WatermelonDS, Mupen64Plus, EmuCoreX. Repointed with a host-override broadcast. Holds the receiver class and string resources.

Emulator.SHIZUKU_MANAGED / Emulator.BROADCAST_MANAGED derive from which override is present, so the two sets can't drift out of sync.

EmulatorSupport becomes a collection (List<EmulatorState>) with isInstalled() / isEnabled() / installedCount / hasAnyEnabled, and is what MainUiState now holds instead of the 18 flags.

Deduplication

• The six broadcast patchers (Armsx1CfgPatcher, Armsx2CfgPatcher, FlycastCfgPatcher, Mupen64CfgPatcher, WatermelonDsCfgPatcher, EmuCoreXCfgPatcher) were identical apart from names, receiver class and string resources. Deleted in favour of one registry-driven BroadcastCfgPatcher.
• PatchResult / DolphinPatchResult / PpssppPatchResult were structurally identical — unified into ConfigPatchResult in the new ConfigCfgPatcher.
• The nine setXEnabled methods collapse to setEmulatorEnabled(emulator, enabled).
• The patch/revert chains in startProxy / stopProxy / recoverPatchedCfgIfProxyStopped / BootReceiver / ProxyService become loops over the registry.
• HomeFragment inflates its toggle rows from Emulator.entries, so dialog_emulator_selector.xml is an empty container instead of nine hardcoded <include>s.

Bug fixes

Four issues surfaced while making the fan-out uniform:

1. Shizuku revert never restored hardcore mode. The user service hardcoded restoreHardcore = false and never reported the pre-patch state, so hardcore stayed off after stopping the proxy — unlike the SAF path, which persists and restores it. The service now detects hardcore before patching, returns it, and the app persists it in the existing *_HARDCORE_WAS_ENABLED prefs and passes it back on revert.
2. BootReceiver and ProxyService only handled ARMSX2 among the six broadcast emulators, so Flycast/Mupen64Plus/EmuCoreX/ARMSX1/WatermelonDS stayed pointed at a dead proxy after a reboot-autostart or a service kill. Both now loop over all of them.
3. A disabled RetroArch was marked as patched on boot. patchRetroArchAndPersist lacked the !skippedNotInstalled guard its Dolphin/PPSSPP counterparts had, so retroarch_patched_this_run was set to true even with RetroArch disabled.
4. PPSSPP Gold was patched while running. The Shizuku service resolves the ini across both PPSSPP package candidates but force-stopped only org.ppsspp.ppsspp, so Gold could overwrite the patched ini on exit. Force-stop is now driven by packageCandidates.

Verification

Debug + release compile, testDebugUnitTest green, including four new cases covering the hardcore round trip (restoreHardcore = true had no coverage at all before) and the uniqueness of the Shizuku wire keys.

On-device:

• Retroid Pocket Nova — registry resolution, enabled-emulator icon cluster, emulator selector dialog, and the enable/disable toggles writing the correct per-emulator prefs keys.
• Android 14 AVD — full Shizuku patch/revert round trip for RetroArch + Dolphin + PPSSPP, including PPSSPP's custom memstick root (root-mode prompt → SAF grant → candidate-path fallback), and the hardcore fix in both directions (on → restored on; off → stays off).

Not yet exercised at runtime: the non-Shizuku SAF patch/revert path, BootReceiver on a real reboot, a broadcast emulator confirming receipt of the override, and the PPSSPP Gold force-stop.