ci(crv): add physical host input builder

[daniele21]

Scope

Adds a Harness-owned reusable workflow for CRV physical two-APK preparation.

• checks out an exact Harness candidate revision with recursive submodules;
• verifies exact source identity and llama.cpp pin;
• builds the real ARM64 local-llm-phone-test release APK as an intentionally unsigned CI input;
• verifies release package identity and ARM64-only native packaging;
• uploads bounded source/SHA/manifest evidence plus the unsigned APK for a consumer-owned pair-signing lane.

Ownership / security

Harness continues to own its source/build/native boundary. No signing key, password, certificate private material, GGUF, or production credential is committed or uploaded. The workflow produces only an unsigned physical-test input; pair signing remains outside Harness.

Validation

CI/workflow + Android packaging is release-sensitive, so expected profile is FULL. Physical device behavior and real-GGUF execution remain CRV-110 REAL_ENVIRONMENT and are not claimed here.

[daniele21]

/preflight full