fix: Music Haptics plays in a container (rebind outside the main executable)

[Ping-2o]

What this fixes

Music Haptics did nothing under LiveContainer, while Vibrations > Controls worked fine. The device log made it exact:

music haptics: switch on, Taptic Engine available, Spotify's output untappable
audio pipeline: Spotify output import unavailable
music haptics: Spotify's output could not be tapped (rebind failed); Music Haptics will not play

The Taptic Engine was available and the switch was on — but Spotify's audio output was never tapped, so the analyzer had no sound to follow. This is the "permission issue" reported for containers: it is not a TCC permission, it is the container's process layout.

Root cause

SGRebindImport only ever scanned the main executable (filetype != MH_EXECUTE -> continue). A container runs the host app as the executable and loads Spotify as a dylib, so Spotify's import slot for AudioOutputUnitStart was never in scope and the rebind always failed. No audio tap -> no analysis -> no haptics.

Changes

• Core/SGRebind.m — walk every loaded image for the symbol instead of the main executable alone, skipping only the mod's own dylibs. This also repairs the Shared/ConnectDiscovery sendto/sendmsg rebinds, which shared the same main-executable-only assumption.
• Shared/Audio/SGAudioPipeline.x — install() no longer uses dispatch_once, which locked a failure in for the whole process when Spotify's image was not loaded yet; it now retries until the rebind succeeds.
• Shared/Haptics/MusicHaptics.x — recover instead of staying dead:
  • switch state and player thread are set up before registration, so a failed registration no longer leaves the feature inert and silent;
  • a failed CHHapticEngine is discarded and rebuilt rather than kept forever;
  • the Taptic capability is re-checked rather than cached;
  • the engine falls back to one built without Spotify's audio session (a container's guest app does not own it);
  • registration is retried on the first foreground, and sg_active is seeded from applicationState.
• Diagnostics/Diagnostics.x — one startup line stating which part is missing (switch … Taptic Engine … Spotify's output tapped|not tapped yet|untappable), since this feature previously had several silent ways to do nothing.

Verification

• scripts/check-layers.sh passes (the Diagnostics addition declares its two symbols locally rather than importing across layers).
• The tweak compiles and links clean for arm64.
• Built and run on device under LiveContainer; the log now reports the output as tapped and Music Haptics plays along.

Only source files are touched — no IPA, .deb, or other build output.